Free Essay


In: Business and Management

Submitted By aguero896
Words 1783
Pages 8

Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels
Home News Forums Mocks Apps



Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 by Ravi Handa in MBA Entrance Hacks • 29 September '11

nick password
Remember me

Forgot password?

New to PaGaLGuY?
First Name Last Name E-Mail Address Sign Up

Sponsored Users

131 Posts •


151 Posts •


(Photo credit: Orin Zebest)

If it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic. Tweedledee in Lewis Carolls Through the Looking Glass.

If the above line confused you, trust me you are not alone. Even God can vanish in a puff of logic. To know how, you can probably jump to the end of this post. To those who choose not to skip let us discuss a few common types of Logical Reasoning problems.

Type 1: Cube problems

A cube is given with an edge of unit N. It is painted on all faces. It is cut into smaller cubes of edge of unit n. How many cubes will have x faces painted?

In these types of questions, the first thing that we need to figure out is the number of smaller cubes. For this, we look at one particular edge of the big cube and figure out how many smaller cubes can fit into this. It will be N/n. So, the number of smaller cubes will be (N/n)3

A cube has 6 faces and none of the smaller cubes will have all faces painted. As a matter of fact, none of the smaller cubes will have even 5 or 4 faces painted. The maximum number of faces, which will be painted on a smaller cube, will be 1/6


Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels

3. This will happen only in the case of the smaller cubes that emerge from the corners of the big cube.

So, number of smaller cubes with 3 faces painted = 8 (Always)

For 2 faces to be painted, we will have to consider the smaller cubes that emerge from the edges of the big cube (leaving out the corners). So, the smaller cubes on every edge will be (N-2n)/n. There are 12 edges in a cube.

So, number of smaller cubes with 2 faces painted = 12 * (N-2n)/n

For 1 face to be painted, we will have to consider the smaller cubes that emerge from the face of the big cube (leaving out the corners and the edges). So, the smaller cubes on every face will be [(N-2n)/n]2 . There are 6 faces in a cube.

So, number of smaller cubes with 1 face painted = 6 x [(N-2n)/n]2

For no face to be painted, we will have to consider the smaller cubes that emerge from the inside of the big cube (leaving out the outer surface which was painted). Imagine this as taking a knife and cutting a slice of width n from every face of the cube. You will be left with a smaller cube with an edge of N-2n. Number of smaller cubes that you can make from the resulting cube is [(N2n)/n]3

So, number of smaller cubes with 0 face painted = [(N-2n)/n]3

Let us take an example to elucidate this type of problem.


A painted cube is given with an edge of 15 cm. Smaller cubes are cut out from it with an edge of 3 cm each. How many cubes will have 3 faces painted, 2 faces painted, 1 face painted and no face painted.


Total number of smaller cubes = (15/5)3 = 125

3 faces painted = 8 cubes.

2 faces painted: Consider an edge of size 15 cm. We have removed the corners that take away 3 cm from each corner of the edge. Now our edge is of 9 cm. 3 cubes of 3 cm each can come from it. There are 12 edges. So, there will be 3 * 12 = 36 cubes.

1 face painted: Consider a face. If we have removed 3 cm from each edge of the 2/6


Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels

face, we will be left with a square of side 9 cm or area 81 sq cm. There can be 9 smaller squares that can be formed on that face with an area of 9 sq cm each. These 9 will be the cubes which will have 1 face painted. There are 6 faces. So, there will be 9 * 6 = 54 cubes.

No face painted: Cut slices of 3 cm each from each face of the cube. We will be left with a smaller cube of edge 9 cm. Number of smaller cubes that can be formed from it is (9/3)3 = 27. So, 27 cubes will have no faces painted.

You can use this to verify the formulas above and also note that 8 + 36 + 54 + 27 = 125. This means that there is no need to find out all four using the formula, just find any three of them and the other would emerge by using the total. In an exam, this might save you some valuable time.

Type 2: Matchstick Game

You are playing a matchstick game with Mr Bond. There are n matchsticks on a table. On a players turn, he can pick any number of matchsticks upto p (p is typically quite smaller than n). Whosoever picks the last matchstick loses the game. It is your turn first. How many matchsticks should you pick (assuming that you are smart and will play to win) that you will always win?

First remove 1 matchstick from consideration, as that would be the matchstick that Mr Bond will pick and lose the game.

Find out Remainder [ (n-1) / (p+1) ] = q

You should pick q matchsticks in the first turn.

After that if Mr Bond picks r sticks, you should pick p+1-r sticks and you will win the game.

Let us see an example.


There are 105 matchsticks on a table and a player can pick any number of matchsticks from 1 to 10. The person who picks the last matchstick loses the game. You are playing the game against Mr Bond and it is your turn first. How many matchsticks should you pick in the first turn such that you always win the game?

Solution: You should pick Remainder [(105 - 1)/(10+1)] = 5 matchsticks to win the game.

Let us look at few scenarios, in which you have picked 5 sticks and there are 100 sticks left on the table. It is Mr. Bonds turn now.



Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels



Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels

Round ID Round 1 Round 2 Round 3 Round 4 Round 5 Round 6 Round 7 Round 8 Round 9

Mr. Bond Picks 5

Sticks Left 100 5 = 95

You Pick

Sticks Left

10 + 1 5 = 6 95 6 = 89


89 8 = 81

10 + 1 8 = 3 81 3 = 78


78 7 = 71

10 + 1 7 = 4 71 4 = 67


67 4 = 63

10 + 1 4 = 7 63 7 = 56


56 10 = 46

10 + 1 10 = 1

46 1 = 45


45 8 = 37

10 + 1 8 = 3 37 3 = 34


34 1 = 33

10 + 1 1 = 10

33 10 = 23


23 2 =21

10 + 1 2 = 9 21 9 = 12


12 9 = 3

10 + 1 9 = 2 3 2 = 1

As only 1 stick is left, Mr. Bond will have to pick it and lose the game. I recommend, that you try out such scenarios with a friend. Nothing validates a concept more than a real-life implementation, especially if it is on a bet. :)

For those who are still wondering what did just happen (as I did when I first read this concept), I suggest you pick up Hitchhikers Guide to the Galaxy and read about how God vanished in a puff of logic.

Author Ravi Handa has taught Quantitative Aptitude at IMS for 4 years. An alumnus of IIT Kharagpur where he studied a dual-degree in computer science, he has also written a book on business awareness.







Of Cubes and Matchsticks - Logical Reasoning Tricks for CAT 2011 : PaGaLGuY News & Channels
Similar Articles
CAT Prep for Working Professionals: How to manage time, juggle work with studies 01 May CAT Quant: The definitive primer to finding the area of a triangle 24 Apr Three types of Reading Comprehension passages that the CAT will throw at you 19 Apr Tags: MBA test prep , Logical reasoning , Cube problems, Matchstick games







#96 • 14 Sep '12 Like Page 5 of 6 #97 • 14 Sep '12 Like

sharmaa.abhay oh great sir...thanks a lot

sayanddude @ravihanda sir ji is there any generalized formula for matchsticks if the last guy to pick the coin wins... will it be the remainder of n/(p+1)???
#98 • 18 Oct '12 Like

vip01 thx ravi sir very usefull cocept... nd nw its perfectly clear
#99 • 24 Nov '12 Like

vip01 hey in round 4 how mr bond pic 4 sticks???
#100 • 24 Nov '12 Like Page 6 of 6

ashissanpui well explained !
#101 • 29 Jun Like

avinashgolla @ravihanda sir any short cut for a cuboid having sides a*b*c and we have find out the no of smaller cubes with 0,1,2 and 3 sides ?
#102 • 26 Aug Like

u4cse08024 @avinashgolla i derived it using the same concept given above, the only change we can do would be to substitute the N with lenght , breadth and height, respectively
#103 • 29 Sep Like 1

Write a comment...

© 2013 PaGaLGuY


About Us



Contact Us




Similar Documents

Premium Essay

Logical Fallacies

...Logical Fallacies Fallacies are common errors in reasoning that will undermine the logic of your argument. Fallacies can be either illegitimate arguments or irrelevant points, and are often identified because they lack evidence that supports their claim. Avoid these common fallacies in your own arguments and watch for them in the arguments of others. • o Slippery Slope: This is a conclusion based on the premise that if A happens, then eventually through a series of small steps, through B, C,..., X, Y, Z will happen, too, basically equating A and Z. So, if we don't want Z to occur, A must not be allowed to occur either. Example:If we ban Hummers because they are bad for the environment eventually the government will ban all cars, so we should not ban Hummers. In this example, the author is equating banning Hummers with banning all cars, which is not the same thing. o Hasty Generalization: This is a conclusion based on insufficient or biased evidence. In other words, you are rushing to a conclusion before you have all the relevant facts. Example: Even though it's only the first day, I can tell this is going to be a boring course. In this example, the author is basing his evaluation of the entire course on only the first day, which is notoriously boring and full of housekeeping tasks for most courses. To make a fair and reasonable evaluation the author must attend not one but several classes, and possibly even examine the textbook, talk to the professor, or......

Words: 1157 - Pages: 5

Premium Essay

Logical Fallacies

...Logical Fallacies Defined Jamie Osborne American InterContinental University Abstract Fallacies can be viewed as a mistake or error. There are many different fallacies with different meanings for each. The following paper will discuss 9 logical fallacies. The paper will also include definitions for each of the 9 fallacies as well as examples of being applied to real life scenarios. Logical Fallacies defined Everyone has gotten into an argument with someone once or twice in their lifetime. Some people have mastered their skills in being argumentative while others are lacking in that department. The following will be a list of 9 different types of argument styles that could take place in one’s argument scenario. We have all been in an argument and more than likely used one or more of these in arguments that we have had in the past. The first logical fallacy to discuss will be Mere Assertion. By definition mere assertion means while arguing one’s point no matter what the opposing party may have to say their argument is right because that person believes it to be the truth. To further explain will an example P1- Mermaids are real and have inhabited the sea since the beginning of time. P2- Mermaids are in fact real and inhabit the sea because I believe they do. C- Mermaids are real and have inhabited the sea since the beginning of time because I believe they do. Therefore due to the fact that I believe that mermaids are real and that they inhabit the sea......

Words: 1322 - Pages: 6

Premium Essay

Logical Falacies

...James Jackson BCOM/275 Week 2 Assignment Logical Fallacies Analysis 1. Personal attack ad hominem. An ad hominem compares the qualities of the person making a claim to the qualities of the actual claim. It is when it is argued that a claim cannot be true because there is a certain lack of quality in the person providing the claim. With this fallacy, it is not the claim itself being analyzed, but the person making the claim. A “personal attack” ad hominem does exactly that – it attacks the person making a claim in order to set them in a negative light. The thought is that a claim cannot possibly be true if the person making the claim is a “bad person”. We see this in the media all of the time with politics. Often pundits in the media will claim that a politician in the opposing party does not have the “moral authority” to claim something because the politician may have been accused of doing something that the media outlet is reporting as morally wrong. A good example of this was early in Barack Obama’s presidency, and even when he was campaigning. During that time some media outlets would dispute a patriotic statement he may have made. They claimed that he could not be patriotic because there was no proof he was even an American citizen since no one had ever seen his birth certificate. This could also be considered a circumstantial ad hominem, as the media was saying that his claimed circumstances refuted his patriotism. 2. Scare tactics. Scare tactics......

Words: 896 - Pages: 4

Premium Essay

Logical Fallacies

...Logical Fallacies American InterContinental University - Online PHIL201-1204A-02 October 20, 2012 Earl Barnett Logical Fallacies Fallacies are statements that might sound reasonable or sketchily true but are actually weak or dishonest. I will discuss and give me interpretation of some common logical fallacies. Mere Assertion & Circular Reasoning Mere Assertion is an argument that lacks factual support. It’s merely an opinion that is formed more so by belief then logical evidence. For example, “Robert is a vampire; I can feel his cold blood when I touch him.” This argument has no real logic behind it, only reasoning that makes sense to the person stating it. Circular Reasoning is an argument that aids support to a statement by repeating itself in a bolder definition. For example, I am human because my mother is human and my mother is human because I am human. Using the method of circular reasoning states that because I was conceived by my mother I am human as well. Both statements in my argument prove each other to be true, which makes my conclusion and premises the same. Ad Hominem & Red Herring Ad Hominem is an argument used to negatively portray ones character. This method of argument redirects ones attention from a certain topic by providing unrelated accusations about the person in support of the topic. For instance, in a court dispute over which parent should be granted full custody of their child, the defending lawyer states that the......

Words: 897 - Pages: 4

Premium Essay

Logical Fallacies

...Logical Fallacies Fallacies are all around us. We see fallacies on the television, newspapers, and radio. People around the world experience logical fallacies on almost a daily basis. A fallacy is defined as “errors or flaws in reasoning” (Axelrod and Cooper 620).Fallacies used in advertisements are; band wagon, begging the question, confusing chronology with casualty, either-or reasoning, equivocating, failing to accept the burden of proof, false analogy, hasty generalization, overreliance on authority, oversimplifying, personal attack, red herring, slanting, slippery slope, sob story, straw man. I have gathered four advertisements that have fallacies. The fallacies are slippery slope, overreliance on authority, and hasty generalization. My first finding is an advertisement with the fallacy slippery slope. The advertiser tells people “Use this 3D White collection together and get a noticeably whiter smile in just two days”. Slippery slope is defined as pretending that one thing inevitable leads to another (Axelrod and Cooper 621). The advertisement has the celebrity Shakira smiling with beautiful white teeth. It has three Crest 3D White products a toothbrush, mouthwash, and toothpaste. Advertiser say’s “Reveal your inner rock star with a 3D White smile”. Also, it claims that “life opens up with a whiter smile”. This advertisement is pretending that life will be better if people use its products. It will also supposedly make your teeth glamorous white. The......

Words: 872 - Pages: 4

Premium Essay

Logical Fallacies

...Ashley Valdez PHIL201 August 31, 2014 Mere assertion: A mere assertion is statement said to be true and believed but has no factual evidence or validation to back it up. Example: He would never cheat on his wife because they are happy and he loves her very much. Circular Reasoning: A circular reasoning is when the argument is the same as the resolution. Example: Mother- “This is what is best for you and I know what is best for you.” Ad Hominem: The term Ad Hominem is the Latin translation for “against the person”. It means when a claim during an argument, that is a personal attack or allegation and is not logical and is irrelevant. Example: “President Obama held a press conference to talk about the serious issue of ISIS but he obviously did not take it that serious because he wore a tan suit and not a grey or black one.” Red Herring: The term refers to fox hunting, when a smoked herring is dragged on the route of hunting to distracted the hounds’ scent. The argument is a sidetrack comment used to deflect from the actual issue at hand. Example: “I know I shouldn’t have spent this much money on a dress, but does it not accentuate my figure nicely?” Pseudo Question: A pseudo question is an open-ended question that has no answer. Example: If god loves all of us, why does he make some people struggle more than others? False-Cause: A false-cause is coming to the conclusion that something occurred by an inaccurate observation. Example:......

Words: 449 - Pages: 2

Premium Essay

Effective Logical Fallacy

...Identify the Logical Fallacies 1. Mabel is not qualified to lead the school board because she used to drink liquor in her 20s. • This is anAd hominem fallacy: It attacks the character of the arguer rather than the argument. It is an error in reasoning because you should focus on the argument. 2. A child can be either an athlete or a good student. • This is an Either-or type fallacy: it presents someone with a limited choice when there are more choices. The error is that people will know they have more choices and discredit your argument. 3. Any change in health care will lead to socialism; we don’t want to live in a socialist country, so we can’t reform health care. • Begging the Question: Using circular reasoning to prove a conclusion. This is done in the news a lot and this type of fallacy goes unnoticed. The error is that the claim is false so the conclusion is false and people will notice this. 4. All teenagers text while they drive; therefore, we should raise the driving age to 21. • Hasty generalization: Using a part to make an inaccurate claim about a whole. This is wrong because if any part of the claim is wrong it will make the whole argument wrong. 5. If we don’t all drive hybrid cars, the world will end in the next decade because of environmental damage. • Slippery slope: Suggesting that one event will automatically lead to a chain of other events. This is wrong because the claim that the world will end isn’t supported be any......

Words: 581 - Pages: 3

Premium Essay

Logical Fallacies in Philosophy

...What Are Logical Fallacies? Unknown AIU Online What Are Logical Fallacies? There are two different kinds of reasoning in philosophy. One uses the logical synthesis of two or more true statements, it is called deductive reasoning. The other generalizes by observing a number of specific examples, it is called inductive reasoning. (Carroll, 2000) Both deductive and inductive reasoning requires us to use sound logic to reach valid conclusions. Without the use of this logic errors can occur, which in philosophy are called logical fallacies. Mere Assertion The first logical fallacy I am going to define is mere assertion. This is an argument of opinion. There is no guarantee that what you say will be expected. But all opinions whether they are believed to be true or not must be supported by evidence. Here is an example of a mere assertion fallacy. My cats love me because they sleep on my bed. Also when I open their cat food they come running, so they must love me. Both of these statements are not supported by evidence. They are just statements of opinion that I believe to be truth. Circular Reasoning The second logical fallacy I am going to define is circular reasoning. This is an argument where your conclusion and premise are the same. It is an argument that asks you to simply accept the conclusion without real evidence. Also it can be an argument that simply ignores an important assumption. So to avoid this fallacy you......

Words: 1313 - Pages: 6

Premium Essay

Many Types of Logical Fallacies

...Some of the many types of Logical Fallacies .American Intercontinental University PHIL 201- 1401B-02 Week 3 Individual Assignment Introduction: Logical Fallacy: A logical fallacy is an error in reasoning. In other words, it is a factual error or a failure to logically support the conclusion in an argument. An argument is a group of statements about a specific topic where a stand is taken applying premises needed to support their conclusion. A fallacy is a type of argument where the person uses bad arguments to support their conclusion but in order to be a fallacy it must be believed some of the time (Eemeren & Grootendorst, 1995). The different types of fallacies are mere assertion, circular reasoning, Ad hominem, red herring, pseudo-questions, false cause, sweeping generalizations, slippery slope, and equivocation or changing meanings. Mere Assertion: Arguments by mere assertion simply mean a person uses a strong statement instead of any real fact to argue a point. Just because an argument is stated emphatically does not mean that statement is in fact true. In mere assertion even if there are facts to the contrary or that contradict the argument it will continue o be supported. Arguments by mere assertion are also considered rhetoric. Rhetoric is supporting the argument despite the fact there is no evidence the argument is true. It is a form of persuasion or blind faith in the mere assertion. Circular Reasoning: Circular reasoning is a type of fallacy where......

Words: 1375 - Pages: 6

Free Essay

Logical Modeling in Systems Analysis

...Logical Modeling in Systems Analysis Table of Contents Topic Page Chapter One Abstract . . . . . . . . . . . . . . . . . . . 3 Chapter Two Introduction . . . . . . . . . . . . . . . . . . 4 Information Systems . . . . . . . . . . . . . . . 5 IS Analysis Phase . . . . . . . . . . . . . . . . 5 Modeling Definition and Concepts. . . . . . . . . 5 Traditional Approach Logical Models . . . . . . . . 7 Object Oriented Approach Logical Models . . . . . . 9 Chapter Three Current Topics in Data Modeling . . . . . . . . . . . 12 Bibliography . . . . . . . . . . . . . . . . . . 14 CHAPTER ONE Abstract Today’s organizations are utilizing their core competencies while exploiting the core competencies of subcontractors to produce highly differentiated and high quality products at a lower cost. Business process reengineering has played a key role in remaining competitive, enabled through information technology. Existence of the automated information system, developed through Systems Analysis and Design, has become a requirement for survival of today’s companies. Process......

Words: 3155 - Pages: 13

Premium Essay

Converting a Physical Data Model to a Logical Model

...Table of Contents Setting up the subject area (if required) 2 Bringing in the tables 4 Assigning appropriate Domains 5 The logical Model 6 Identifying a many to many relationship 7 Replacing a mapping table 7 Renaming Logical Model 15 Entity Names 15 Relationship Names 16 Attribute Names 16 Revisiting Physical Model 19 Relationship Naming 20 FINAL PRODUCT 21 Logical VS Physical 21 Setting up the subject area (if required) 1. Open the target and source Erwin models in the same instance of Erwin. 2. If required create a new subject area in the target model where the tables are going to be copied. Figure 1 – Creating a new subject area 3. Change the default theme to ‘Classic Theme’ (right click on the diagram page and click properties ER Diagram Editor will open up. Change the Theme on the ‘General’ tab) Figure 2 – Selecting a Theme Bringing in the tables 1. Select the tables and relationships (if applicable) from the source model file and paste them in the target model while both models are in Physical mode. Figure 3 – Importing/copying the tables 2. Verify that all the tables you need are copied in the Erwin target model. 3. You can close the source model at this stage (recommended) Assigning appropriate Domains 1. Right click on the table and select ‘column properties’. 2. Assign the correct domain parent to all the columns. Figure 4 Assigning Domains to the columns 3. Once you have assigned......

Words: 1187 - Pages: 5

Premium Essay

Logical Thinking

...Logical thinking Logical thinking can be explained in simple words as something that helps the human being to make the right decision or solve unsolved problems. Most of the humans think, but most of them do not reason correctly and that process is called logic and it needs training sometimes. Understanding the logical way of thinking makes that person think critically and all the information needed and come to a conclusion. This process of thinking is different form other thinking process as it involves a lot of critical thinking. This process or sense is only given to the human being and not any other animals even though some people claim that Chimpanzee’s a category in monkey family also have that. This logical thinking involves a lot of critical thinking and it could be something that happens every day in our life and we might be trying to solve that problem in a different way. Best example that Bejoy can think will be something that he does on his off days as his wife goes to work and he end up spending time taking care of his 2 yr old son. His main purpose those days is how to make his son speak his language very well as language is related to the culture that Bejoy was brought up and he wanted his son to grow up in that same culture. As soon as his wife leaves, he make plans on how to teach his son the language in a way that is going to interesting for both him and his son. The way of handling the situation will be different every day and it involves a lot of......

Words: 386 - Pages: 2

Premium Essay

Logical Fallacies we identify Logical Fallacies? By: Tabitha Harris American InterContinental Online University July 16, 2013 Abstract This purpose of this paper is to identify and explain what literature experts call Logical Fallacies. This document will include reasonable vocabulary, logical definitions, and sound examples of how to and how not to include these fallacies into your writings. There will be some suggestions made to assist with recognizing and examining some of the logical fallacies located within the writings of others, as well as in your own. By the end of this paper, your thoughts will be enlightened, and your knowledge of logical fallacies stronger, whether you’re a reader, writer, or just someone looking to learn. How do we identify Logical Fallacies? Logical Fallacies are arguments or false statements that appear to be true, when in fact, they’re not. Logical fallacies can also be accurate and are used to pursue someone to accept a single thought or feeling. People use logical fallacies to prove a point and to support reasoning behind a thought. There are different types of fallacies that I will go over in this paper. Fallacies often dilute arguments and by learning to recognize them in your own writing helps boost your ability to identify them in others’ writings, as well. This document will point out and explain key fallacies to look for in your writings and literature in general. (Career Education Corporation [CEC], 2010) LOGICAL FALLACIES: ...

Words: 892 - Pages: 4

Premium Essay

Logical Thinking

...Logical Thinking Worksheet * Use the following questions to guide you through your exploration of logical thinking and arguments. Answer the questions as completely as possible, and provide examples where needed. 1. What is a logical argument? * To understand the meaning of the logical argument, we need to know first what an argument is. According to (, 2010), an argument is an attempt to demonstrate the truth of a conclusion based on premises or statements, relating this definition of argument with logic, we can deduce that these statements or premises have to follow the principles of reasoning in a clear and consistent manner. * As an example, the argument “I need to study to fail that math test”, does not make sense and does not follow the principles of the logical argument, the logical argument should be “I need to study to approve that math test“. 2. When and how do we use them? Do we use logical arguments in our daily life in their basic forms of inductive and deductive thinking, in inductive because we always tend to use observations and evidence to get a conclusion and deductive because we usually based our decisions in fact or truth premises. 3. What parts do they contain? According to (Virtual School, 2004), the parts of a logical argument are called propositions that are classified in premises, inferences, and conclusion. Premises are propositions that begin an argument, inferences, are propositions that are derived from one......

Words: 1436 - Pages: 6

Premium Essay

Logical Model

...descriptionUnit priceCreated | PRODUCT_ID: INTEGERPROD_DESC: VARCHAR(50)CATEGORY_ID: INTEGERCATEGORY_DESC: VARCHAR(50)UNIT_PRICE: FLOATCREATED: DATE | Sales | Store IDProduct IDDateItems soldSales amount | STORE_ID: INTEGERPRODUCT_ID: INTEGERDATE_ID: INTEGERITEMS_SOLD: INTEGERSALES_AMOUNT: FLOAT | Store | Store IDStore DescriptionRegionRegion namecreated | STORE_ID: INTEGERSTORE_DESC: VARCHAR(50)REGION_ID: INTEGERREGION_NAME: VARCHAR(50)CREATED: DATE | Logical/Physical data model: Logical data model: A logical data model describes the data in as much detail as possible, without regard to how they will be physical implemented in the database. Features of a logical data model include: * Includes all entities and relationships among them. * All attributes for each entity are specified. * The primary key for each entity is specified. * Foreign keys (keys identifying the relationship between different entities) are specified. * Normalization occurs at this level. The steps for designing the logical data model are as follows: 1. Specify primary keys for all entities. 2. Find the relationships between different entities. 3. Find all attributes for each entity. 4. Resolve many-to-many relationships. 5. Normalization. Physical data model: It represents how the model will be built in the database. A physical database model shows all table structures, including column name, column data type, column constraints, primary key, foreign......

Words: 381 - Pages: 2