5 ways to improve your GMAT score - Part 3/5

3. To ace the Quantitative section, work on math reasoning also

It is imperative that you know an array of basic math concepts, like, difference of squares, number properties, rules of divisibility, Venn diagrams, and combinatorics. To perform well, however, you need to far surpass basic competency in using these concepts. You need to be able to recognize patterns, hypothesize and check inequalities/equations, diagram complex problems, develop a sense for numbers (understanding numbers and their relationships) and visualize your calculations and methodologies freely. So work on building math concepts and math reasoning parallely.

What math skills are tested on the GMAT?

 

What math skills are tested on the GMAT?

The quantitative section of the GMAT is predictable. If you grasp the fundamentals, you
will be able to ace the GMAT math section.

What are the fundamentals skills, you should focus on…

 

#GMAT MATH SKILL 1: ARITHMETIC

The GMAT tests your ability to do the following:

• Work with fractions, decimals and ratios
• Understand properties and concepts of real numbers
• Work with multiples and factors
• Understand and apply concepts of percentages in sums dealing with profit loss discount, simple and compound interest
• Calculate indices, exponent and surds
• Know and apply counting methods (permutation and combination)
• Understand probability and apply this concept in word problems
• Work on sets (Venn diagrams)
• Understand descriptive statistics (mean, median, mode and standard deviation)

        

#GMAT MATH SKILL 2: ALGEBRA

The GMAT tests your ability to do the following:

Solve and manipulate

• Equations
• Inequalities
• Algebraic expressions (isolate variable and solve for a variable)
• Functions

#GMAT MATH SKILL 3: GEOMETRY

The GMAT tests your ability to do the following:

Understand the properties of

•  Lines, triangles, quadrilaterals and circles
• Solids (cuboid, cylinders, spheres.)

Use the concepts of

• Coordinate geometry
• Trigonometry

 #GMAT MATH SKILL 4: RATIOS and PROPORTION

The GMAT tests your ability to do the following:

• Work with ratios and measurement problems

Apply the concept of ratios in

• Time and work problems
• Time speed and distance problems
• Mixtures and solutions

Once you get the grasp of the fundamentals, then you need to apply them in problems.

Time management is also an important parameter during problem solving.  You need to arrive at an answer in less than 2 minutes.

Need help in math,, Feel free to contact me

My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/ 

GMAT math thinking skills 10

 GMAT tests your logical skills as well as your knowledge of math concepts.  To score high, you need to remember various formulas, theorems. Also you need to master critical problem-solving skills.

Today I am going to  take you through one problem -solving skill –

Counting skills

Take this problem .

This sum requires higher order thinking

There are two ways to solve this question

 

Method 1:Using pattern recognition

 Lets say,  you didn’t know the concept of counting and permutation and combination

First focus on the 8x8 grid...

Take the smallest unit of chessboard. It’s a 2x2 grid

How many rectangles can you count?

All the squares are rectangles too.

First count squares  there are 5

How many rectangles can you count? There are 4.

In total there are 9 . 

If you observe........ 9  = 1+8

these numbers follow the cube series

 

Now take a  3x3 grid

How many rectangles can you count?

First count squares  there are 14

How many rectangles can you count? There are 22

In total there are 36 . 

If you observe ..........36  = 1+8+27

these numbers follow the cube series

 

Always remember 

the number of rectangles in a grid follow the cubic series 1³ 2³ …3³…

So in a chess board.. the number of rectangles is the  sum of the cubes from 1³ to 8³

 Hence 1³ +2³ + 3³+4³ +5³ +6³ +7³ +8³ =1296

  

 

 

Method 2:Using principles of counting

The chess board has 8 rows and 8 columns. a 8x8 grid.

All squares are rectangles. So you need to count the squares also.

 

Okay.. First look at the gird..

Can you observe the number of horizontal lines? There are 9 lines

Similarly

Can you observe the number of vertical lines? There are 9 lines

 

If you observe… to draw a rectangle. You need to select two horizontal lines and two vertical lines.

The point of intersection of these lines form a rectangle.

So how do we choose two lines out of 9. 

Use combination.

To select 2 horizontal lines = ⁹C₂

To select 2 vertical lines = ⁹C₂

Now as per the rules of counting…you need to multiply

⁹C₂ x ⁹C₂ = ((9x8)/ (1x2) ) x ((9x8)/ (1x2) ) = 1296

There are 1296 rectangles in a chessboard.

 

To know more about Math problem solving skills.. Feel free to contact me

 My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/

Lets try another sum

Solution is here

http://letsgmat.blogspot.com/2020/11/gmat-math-thinking-skills-7.html

 

3 ways to improve your math skills - GMAT math tips

Math is tough for some of us.

The reason - The way, math was taught to us in school or college.

Can it be mastered now?

Yes, you can...

GMAT  mainly tests your mathematical reasoning.

Your ability to 

• reason with numbers and symbols.
• apply principles/formula and solve questions
• evaluate cases or arguments
• strategize for a solution
• identify patterns and use logic
• check data efficacy and more.

So if you are taught skills ( Skills are different from math concepts), you will be fine.

Ping me if you would like to know more about the math skill-development course .

My contact details are here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/

So how we do work on our math skills. Here are 3 ways, which can help you hone your general math skills

1.Make math part of your daily life... practice it without even thinking

For example, if a dress that’s regularly $50 is on sale for 30% off, what is the sale price?  

Do simple calculation.

Or if you have to travel 20 miles. You are going at a speed of 20 miles per hour. How long will you take?

2.Use mental math everyday

20+30+45+60 = ??? don’t use calculator.

What is 15 squared or what is 20 squared…

Everyday spend 5 - 10 minutes working on basic computation

 

3.Practice diagramming

Always picture a math problem.

Make few circles/ draw connections/ some stick figures….

Here are sample images for math problems

If you have any queries regarding math preparation.. ping me

Happy learning... 

GMAT math thinking skills - 9

GMAT tests your logical skills as well as your knowledge of math concepts.  To score high, you need to remember various formulas, theorems. Also you need to master critical problem-solving skills.

Today I am going to  take you through one problem -solving skill –

Attention to detail

Take this problem .

I am going to show you, two ways to solve this sum

Method 1 :  The traditional approach

You need to choose the numbers which negate each other

For example Row 6 column 6 = 36.

Row 5 column 6 = -30 and  Row 1 column 6 is -6

So 36+ (-30-6) =0.

You need to choose the right numbers

 Add the remaining numbers you will get the answer

I have highlighted the different combinations with letters

1J	-2I	3H	-4J	5D	-6A
-2	4G	-6C	8G	-10I	12I
3J	-6B	9H	-12H	15E	-18B
-4F	8G	-12F	16F	-20E	24B
5E	-10	15	-20G	25D	-30D
-6	12	-18C	24C	-30A	36A

 

Numbers left =  12 15  -6 -10 -2

Sum = 9

This method takes a long time

Method 2: Pattern recognition

This approach is a lot faster.

If you look at the numbers column-wise can you see a pattern(ignore signs)

column 1: 1 2,3,4,5,6

column 2: 2x1,2x2,2x3,2x4,2x5,2x6 

.

.

column 6: 6x1,6x2,6x3………..6x6

When the signs are inserted, then a pattern emerges  i.e. = 1-2+3-4+5-6

lets calculate the sum of the repeating pattern 1-2+3-4+5-6 = -3

Hence column 1 adds upto -3

Next column will be -2+4-6+8-10+12 = -2 x(1-2+3-4+5-6)= -2x-3 = 6

Next column will be 3 x(1-2+3-4+5-6)= 3 x-3 = -9

Next column will be -4 x(1-2+3-4+5-6)= -4 x-3 = 12

Next column will be 5 x(1-2+3-4+5-6)= 5 x-3 = -15

Next column will be -6 x(1-2+3-4+5-6)= -6 x-3 = +18

Answer = -3+6-9 +12-15+18 = 9

If you want to maximize your math scores in the GMAT.. Lets have a chat...

My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/

Lets try another sum

Solution is here

http://letsgmat.blogspot.com/2020/11/gmat-math-thinking-skills-7.html

 

How to overcome GMAT math anxiety?

Do you have a non-math background?

Has it been a long time since you touched your math books?

Feeling anxious?

Many students ask me this question.

"Can I ace the GMAT math, if I have a non-math background?"   Yes, you can.

Remember GMAT tests you on math reasoning primarily. 

To overcome anxiety, You need to learn math concepts.+ You need to develop math skill-sets too.

Formula/theorems (Area of the circle, HCF and LCM of numbers...)  are the math concepts.

So what are the math skill-sets?

Definition of a skill-set: A skill-set is the combination of knowledge and abilities that you've developed through your life and work. You use these skills-sets to tackle problems.

We, at semantics, have developed modules, which can hone a students math and verbal skill sets.

Let me take you through one math skill-set. 

Problem Decomposition  

Definition: Decomposition is  the process of breaking a problem down into smaller parts to make it easier to tackle.

If you have a non- math background, you might find it difficult to comprehend word problems.

One way to analyze word problems is - break problems into meaning-full chunks.  

You need to

1. break the problem into  2 or more segments.

2. Analyse each segment.

3. Infer data (if necessary)

4. Diagram information…

Only after all this, you write equations and solve..

Let me demonstrate the above process via a math question

Lets take this problem and break it into segments.

Segment 1: "Each machine produces 1 toy every 3 minutes"

Segment 2: "After replacement : 40% of machines  produce 1 toy every 2 minutes"

When you process segment 2, you should also infer additional information.

This information is not explicitly mentioned.

Inference:  If 40% of the machines produce 1 toy every 2 minutes, then 60% of the machines produce 1 toy every 3 minutes

 

Segment 3: "Percentage increase in the number of toys produced in 60 minutes."

 

After breaking the problems into segments, you should use one of the many problem solving approaches.

Lets use this approach:  substitution of numbers.

Assume 100 machines are there initially

 

Segment 1:

Total time is 60 mins.

1 machine produces a toy every 3 minutes . Hence 20 toys are produced by 1 machine in 60 mins.

There are totally 100 machines.. Hence number of toys produced = 100 x 20=  2000 toys

 

Segment 2:

Total number of machines = 100

 type 1: 40% of the machines (i.e. 40 machines) produce 1 toy every 2 minutes,

type 2: 60% of the machines (i.e. 60 machines)  produce 1 toy every 3 minutes

Lets calculate number of machines produced by  type 2 first.. 

1 machine produces a toy every 3 minutes . Hence 20 toys are produced by 1 machine in 60 mins. Totally 60 machines.. Hence 60x20= 1200 toys  

 

Let us calculate number of machines produced by type 1.

1 machine produces a toy every 2 minutes . Hence 30 toys are produced by 1 machine in 60 mins. Totally 40 machines.. Hence 40x30= 1200 toys

so totally 1200+1200 = 2400 toys are produced.

Segment 3:

Percentage change =  (2400-2000)/2000 x 100 = 20% 

Hope you have understood this problem solving process.

Even if you have a non-math background, you can learn these processes and apply them on a wide genre of questions.

If you need help in GMAT math or verbal..

Feel free to reach out:

My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT

Happy learning. 

 

GMAT math thinking skills - 8

GMAT tests your logical skills as well as your knowledge of math concepts.  To score high, you need to remember various formulas, theorems. Also you need to master critical problem-solving skills.

Today I am going to  take you through one problem -solving skill –

Problem analysis with a diagram

Take this problem .

If you follow approach 1. 

You will use many formulas and theorems. You will get an answer, but it will take more time.

If you follow approach 2.

 You will minimize the number of formulas used. You will use your logical skills and reduce complex computation. You will solve questions faster.

In GMAT time-taken per question is the key. If you solve questions in less than 30 seconds, then you will have more time in the bank to solve harder questions. You will also be able to complete the section in the allotted time.

Penalty marks for un-attempted questions are huge.

Can logic be taught?

Yes!  Logic can be taught. If the tutor teaches you reasoning skills and demonstrates those skills on a wide range of problems, your thinking will get re-oriented. You will be able to solve questions using more than one approach.

I feel Logic is best taught in a tutor driven class, not through generic videos

If you need help in GMAT, here are my details

My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/

Now let us understand both the approaches.

Approach 1

This approach involves formulae/theorem...

Area of square ABCD = side²

Side = 8. Hence area =64

F and E are midpoints of the respective sides. AB=AD=8

Hence AF=FB=4 and AE=ED=4

Triangle AEF, Triangle BFC and Triangle EDC are right angled triangles. Hence we can use Pythagoras theorem

This approach was time consuming. Also, This approach involves lots of calculation.

Approach 2 - faster approach

When you encounter geometry problems, look at the picture for few seconds.

Can you observe a square and 4 triangles?

Spend time observing the pictures and look for clues.

The area of shaded portion is equal to the area of the square – (sum of the area of the 3 triangles).

This approach requires you to know the area of the triangle = 0.5 x base x height.

Now let’s analyze the figure. F and E are the midpoints

The sides of the square are 8

Area of triangle AEF = 0.5x4x4 = 8

Area of triangle EDC = 0.5x4x8 = 16

Area of triangle FBC = 0.5x8x4 = 16

Area of square =64

Area of shaded region = 64- 16-16-8 =24

This approach is far easier and involves less calculation.

So always use logic to arrive at answers faster

 

 

GMAT math thinking skills 7

You will encounter word problems like this in the GMAT.

Most of you will write equations and solve this sum. 

That approach takes a lot of time.   

I am now going to show you, two ways to solve this sum

Method 1 :  The traditional approach

This approach takes time, for those, who are not comfortable with math.

You are also prone to calculation errors.

Method 2: Substitution of numbers

This approach is a lot faster.

You can save lots of time, If you use numbers instead of variables like X and Y. You can use this approach to solve various types of sums, from different areas.

 

Let’s choose numbers such that k is greater than m.

 Lets put P =100 and E = 10 . You can choose any number…

Hence option D is correct.

If there are many variables, use method 2 to arrive at the answer faster. 

Do you want to try another question in this series.

Give it a shot

 

Solution is here : http://letsgmat.blogspot.com/2020/09/gmat-math-thinking-skills-6.html

If you want to maximize your math scores in the GMAT.. Lets have a chat...

 

My contact link is here:

LinkedIn profile : https://www.linkedin.com/in/georgeanand/

Facebook learning group: https://www.facebook.com/groups/semanticsGMAT/

 

How can I get Q 51 in GMAT math

First, some popular questions..

I have a non math background... Can I get Q  51 (99 percentile) in math?

Yes you can.....I have helped people, who had a fear of math (before they met me), score Q 51.  So it is possible for a person with a non math background score high.

Remember - The GMAT quantitative section tests your math skills as well as your reasoning skills....

I am good at math... Yet in my mocks, I am not able to score above Q 45.. Why?

Your concepts may be good, but there is a still big gap in your preparation. I will explain the missing link below.

I know the concepts.. I can solve the questions.. But I take a long time.. How can i solve the question faster..... in less than 30 seconds?

You will be able to solve many of the sums in the GMAT, if you have 2 hrs for the math section. But you have only 62 mins to do 31 questions.

That works to 2 minutes or less..per question. There is a lacuna in your preparation. I will explain the missing link below.

I have been teaching GMAT since 2008. I have sat with a number of students . I explored their thought process. Some students are good at grasping concepts and applying the concepts in a math sum. Others go blank. They are not able to start the problem solving process.. why???.. 

There is something missing....

The missing link is mathematical reasoning..

some of the students have it in them.. others do not. 

here is a list of math concepts which are tested in GMAT

Knowledge of math concepts will help you.. But from my analysis you need more..

Here are list of additional skills

Math concepts + math skills = success in the exam.

This tutorial video will explain some of these skills.. Feel free to ping me if you need more info on these skills. 

To reach me:

Facebook group: https://www.facebook.com/groups/semanticsGMAT

Linkedin profile: https://www.linkedin.com/in/georgeanand

Math reasoning skills can help you solve questions in less than 30 seconds..

Check this sum and follow the series

Check the solution here

http://letsgmat.blogspot.com/2020/07/gmat-math-thinking-skills-3.html

GMAT math thinking skills 6

 

Many students get stumped when they see a math problem. They do not know how to start and how to proceed. They read the question many times, trying to spot the clues. Sometimes the clues are hidden in the questions. Some times they are explicit.  

If you fall into this category.. Fear not.. There is an approach which can help you approach  math questions better.

Follow this 3 step problem solving process.

1. Collect the data given

2. Diagram the problem.

Break the question into segments. Do not read the entire question. After reading a segment, jot down the data on paper. Represent the data in the form of a table or any diagram.

3. Recall a math formula/concept which you can apply and solve

Let us use this approach and solve this problem

Step 1: Collect the data given

Data: 

1. 60 people are there
2. No two rank the same
3. (3/5) of 60 ranked vanilla last = (3/5)x 60 =36
4. (1/10) of 60 ranked vanilla before chocolate = (1/10)x 60 =6
5. (1/3) of 60 ranked vanilla before strawberry = (1/3)x 60 =20

Step 2. Diagram the problem.

Lets diagram the data. I have ranked the data 1,2,3

36 people ranked V(vanilla) last

6 people ranked V before C(chocolate). There are two cases here.  V is ranked 1 or 2.

20 people ranked V before S(Strawberry). There are two cases here. V is ranked 1 or 2.

If you observe 

Out of 60, 36 people ranked V last. Balance  = 60-36 =24 

There are 24 people..

6 people marked V before C (group 1) and 20 people marked V before S(group 2). Hence there should be some people common to both groups ( as 20+6 is not 24) These people should have ranked V first

3. Recall a math formula/concept which you can apply.

Set theory can be used to represent data which is common in two groups

20 is group 1.. 6 is group 2. X represents the number of people, who are common to both groups.

Formula: A union B =A+B-A intersection B

24 =20+6-x

x= 2

Follow this 3 step process. and remember to diagram data. 

This approach makes life easier in the GMAT.

GMAT math thinking skills 4

Topic: Number system

Difficulty level: Average

You will get word problems like this in your exams.

The concepts involved in this problem are

1. Equations

Method 1:

This method will take time as you need to read the question,  write equations, and solve them. Time consuming!!

First let us assume variable x

Method 2:

The previous approach involves equations. Some of us

• don’t like solving equations
• tend to make errors while solving equations..

This approach is faster, involves using answer options as an additional tool to arrive at the answer

First you need to arrive at the equation as described earlier

Hence option D should be the correct answer

Take-away:

Use the answer options . substitute them in the equation and check if  the Left hand side of the equation  = right hand side of the equation)

Watch this tutorial video and understand mathematical reasoning skills..

You can excel in math once you learn these skills.

Ready for more

Try another sum

Solution here

http://letsgmat.blogspot.com/2020/08/gmat-math-thinking-skills-5.html