SOLVED PAPER 2020 (CDS) (II) (Elementary Mathematics)

Total Questions: 100

41. A car did a journey in t hours. Had the average speed been x km/h greater, the journey would have taken y hours less. How long was the journey?

Correct Answer: (b) x(t - y) t y⁻¹
Solution:

42. When a ball is allowed to fall, the time it takes to fall any distance varies as the square root of the distance and it takes 4 s to fall 78.40 m. How long would it take to fall 122.50 m?

Correct Answer: (a) 5 s
Solution:Given, t = k√d,

43. Solve the following equation

Correct Answer: (c) 2 < x < 3
Solution:


44. The Euclidean algorithm is used to calculate the

Correct Answer: (d) HCF of two integers
Solution:Euclidean algorithm is used to calculate the HCF of two integers.

45. If radius of a sphere is rational, then which of the following is/are correct ?

1. Its surface area is rational.
2. Its volume is rational.

Select the correct answer using the code given below.

Correct Answer: (d) Neither 1 nor 2
Solution:

46. Solve the following equation

Correct Answer: (b) 1
Solution:


47. If cos θ + sec θ = k, then what is the value of sin²θ - tan²θ ?

Correct Answer: (b) 4 - k²
Solution:

48. ABC is a triangle inscribed in a semicircle of diameter AB. What is cos(A + B) + sin(A + B) equal to?

Correct Answer: (d) 1
Solution:We have,

49. Consider the following statements:

Correct Answer: (d) Neither 1 nor 2
Solution:We have,

50. What is the magnitude (in radian) of the interior angle of a regular pentagon?

Correct Answer: (c)
Solution: