Today I would like to discuss a very known topic Data Interpretation of Quantitative Aptitude section. Around 34 sets of Data Interpretation are asked in almost every exam. As this is a scoring section, you should practice more to fetch good number of marks.
Steps to solve problems of Data Interpretation: Tables
 Tables are the method of systematic presentation of facts and figures in various rows and columns.
 Before start solving the question, always have a first look of how data is presented.
 Get a proper understanding of presented data.
 Then, start solving the questions using the given data.
 If required, add all the values horizontally and vertically first. Then proceed to questions.
Problems with Solution
Problem1: Study the following table carefully and answer the questions:
SCHOOLS

STANDARDS


I

II

III

IV

V


A

40

55

45

60

45

B

50

60

60

45

55

C

35

50

55

45

50

D

45

55

45

50

45

E

50

50

45

60

50

1. Which school has highest total number of students taking all the standards together?
2. Which standard has lowest total number of students taking all the schools together?
3. What is the ratio of students studying in standard III of schools A and B to those studying in standard V of schools A and B together?
4. What is the average number of students studying in standard I from all schools together?
5. Number of students studying in standard IV of school E is what percentage of students studying in standard IV from school D?
Solution: Firstly, take a minute to read the table and analyze it. After reading the question,You will come to know that you will need the sum of all the rows and columns. So, before start solving the questions, get a sum of all rows and columns.
Now, lets start solving the questions
1. Highest total number of students taking all the standards together
⇒ Maximum value of last column = 270 i.e. School B
2. Lowest total number of students taking all the schools together
⇒Minimum value of last row = 220 i.e. Standard I
3. Standard III of school A and B : Standard V of school A and B :: (45+60) : (45+55)
⇒ 105: 95
⇒21: 19
4. Average number of students studying in standard I from all schools together
⇒ `(Number of students)/(5)` = `(220)/5` = `44`
5. Let number of students studying in Standard IV from school E = `x` % of number of students in Standard IV from school D
⇒60 = `x`% of 50
⇒ `x` = `(60/50) times (100)` = `120`
Therefore, 150% is the answer.
Problem2: Study the following table carefully to answer the questions
1. Number of boys in arts stream in year 2004 is what percentage of total number of boys for all years together in Arts stream?
2. What is the ratio of total number of boys to the total number of girls, taking all the streams together, for year `2005`?
3.What is the average number of girls from commerce steam for the given years?
Solution: Study the table first, three streams are mentioned i.e. arts, science and commerce and the students are divided into girls and boys sections.
1. Number of boys in arts stream in year `2004` = `800`
Total number of boys for all years together in Arts stream= `3300`
⇒ `800` = x % of `3300`
⇒ `x` = `(800)/(3300) times 100`
⇒ `x`= `24.24`
2. Total number of boys for year `2005` : Total number of girls for year `2005`
⇒`700+ 800+900` : `500+ 800+ 500`
⇒ `2400`: `1800`
⇒`4`:`3`
3. Average number of girls from commerce steam for the given years
⇒`(600+600+700+800+500)`/`5`
⇒`(3200)/5`
⇒`640`
I hope you understood the above problems, you are free to ask any query anytime.
3. What is the ratio of students studying in standard III of schools A and B to those studying in standard V of schools A and B together?
4. What is the average number of students studying in standard I from all schools together?
5. Number of students studying in standard IV of school E is what percentage of students studying in standard IV from school D?
Solution: Firstly, take a minute to read the table and analyze it. After reading the question,You will come to know that you will need the sum of all the rows and columns. So, before start solving the questions, get a sum of all rows and columns.
SCHOOLS

STANDARDS


I

II

III

IV

V

Total


A

40

55

45

60

45

245

B

50

60

60

45

55

270

C

35

50

55

45

50

235

D

45

55

45

50

45

240

E

50

50

45

60

50

255

Total

220

270

250

260

245

Now, lets start solving the questions
1. Highest total number of students taking all the standards together
⇒ Maximum value of last column = 270 i.e. School B
2. Lowest total number of students taking all the schools together
⇒Minimum value of last row = 220 i.e. Standard I
3. Standard III of school A and B : Standard V of school A and B :: (45+60) : (45+55)
⇒ 105: 95
⇒21: 19
4. Average number of students studying in standard I from all schools together
⇒ `(Number of students)/(5)` = `(220)/5` = `44`
5. Let number of students studying in Standard IV from school E = `x` % of number of students in Standard IV from school D
⇒60 = `x`% of 50
⇒ `x` = `(60/50) times (100)` = `120`
Therefore, 150% is the answer.
Problem2: Study the following table carefully to answer the questions
YEAR

STREAM


ARTS

SCIENCE

COMMERCE


BOYS

GIRLS

BOYS

GIRLS

BOYS

GIRLS


2001

500

400

600

500

600

600

2002

700

600

700

600

700

600

2003

600

500

500

500

800

700

2004

800

600

900

900

800

800

2005

700

500

800

800

900

500

1. Number of boys in arts stream in year 2004 is what percentage of total number of boys for all years together in Arts stream?
2. What is the ratio of total number of boys to the total number of girls, taking all the streams together, for year `2005`?
3.What is the average number of girls from commerce steam for the given years?
Solution: Study the table first, three streams are mentioned i.e. arts, science and commerce and the students are divided into girls and boys sections.
1. Number of boys in arts stream in year `2004` = `800`
Total number of boys for all years together in Arts stream= `3300`
⇒ `800` = x % of `3300`
⇒ `x` = `(800)/(3300) times 100`
⇒ `x`= `24.24`
2. Total number of boys for year `2005` : Total number of girls for year `2005`
⇒`700+ 800+900` : `500+ 800+ 500`
⇒ `2400`: `1800`
⇒`4`:`3`
3. Average number of girls from commerce steam for the given years
⇒`(600+600+700+800+500)`/`5`
⇒`(3200)/5`
⇒`640`
I hope you understood the above problems, you are free to ask any query anytime.