SOLVED PAPER 2021 (CDS) (II) (Elementary Mathematics)

Total Questions: 100

71. If three positive numbers are in the ratio 2 : 3 : 5 and the sum of their squares is 1368, then what is sum of the numbers?

Correct Answer: (c) 60
Solution:


72. Consider the following inequalities

Correct Answer: (a) 1 only
Solution:



73. Let work done by (3n - 1) men in (2n + 1) days be x and work done by (3n + 1) men in (4n - 3) days be y. If x : y = 6 : 11 then what is the value n?.

Correct Answer: (b) 7
Solution:



74. Solve it ?

Correct Answer: (c) Both 1 and 2
Solution:




75. A person wishes to fence 375 m² rectangular garden. He has 65 m of barbed wire and is able to fence only three sides of the garden. What is the perimeter of the garden?

Correct Answer: (a) 80 m
Solution:




76. (Questions 76-79) Consider the following for next four questions that follow.

The following pie charts show the percentage of different categories (A, B, C, D, E and F) of employees in a company in the year 2019 and 2020. The total number of employees was 4000 in 2019 and 5000 in 2020.

There are two categories of employees in 2019 whose total strength remained the same in 2020. What are these two categories ?

Correct Answer: (d) C and D
Solution:Given pie chart,

Hence, option (d) is correct.

77. In which one of the following categories of employees, the percentage change in number of employees in 2020 was maximum as compared to 2019?

Correct Answer: (b) B
Solution:

78. What was the percentage increase of category-E employees in 2020 as compared to that in 2019?

Correct Answer: (b) 25%
Solution:It is already solved in Questions (77).
The percentage increase of category-E employees in 2020 as compared to that in 2019 is 25%.
Hence, option (b) is correct.

79. There are two categories of employees whose strength increased by same percentage in 2020. What are the two categories

Correct Answer: (d) A and C
Solution:It is already solved in Question (77).
For category -A and category -C of employees strength increased by same percentage i.e., 37.5%.
Hence, option (d) is correct.

80. (Questions 80-83) Consider the following for the next four questions that follow.

The following Bar chart gives the production of cars by three different companies X, Y and Z in different years

The percentage increase in the total production of cars from 2014 to 2018 was

Correct Answer: (b) 100%
Solution: