SOLVED PAPER 2023 (CDS) (II) (Elementary Mathematics)

Total Questions: 100

71. Which of the following is/are identity/identities?

Correct Answer: (c) Both I and II
Solution:

72. If 7sin⁴ θ + 9cos⁴ θ +

42 sin² θ = 16, 0 < θ < π/2,
then what is tan θ equal to?

Correct Answer: (d) 1/√3
Solution:

73. An isosceles triangle has its base length 2a and its height is h. On each side of the triangle a square is drawn external to the triangle. What is the area of the figure thus formed?

Correct Answer: (b)
Solution:

74. Solved

Correct Answer: (c) 1
Solution:

75. Which one of the following is a factor of

a² - b² - c² + 2bc + a + b - c ?

Correct Answer: (d) a - b + c + 1
Solution:

76. Solved

Correct Answer: (b)
Solution:

77. Solved

Correct Answer: (d) 20
Solution:

78. A train completely overtakes two persons, walking in the same direction with speeds 3 km/h and 4 km/h in 9 sec and 75/8 sec, respectively. What is the length of the train?

Correct Answer: (b) 62.5 m
Solution:

79. A person bought an article and sold it at a profit of 20%. Had he bought it at 20% less, what would have been the profit percentage if the selling price had been the same?

Correct Answer: (c) 50%
Solution:

80. If 2s = a + b + c then what is

s² + (s - a) (s - b) + (s - b) (s - c)
(s - c) (s - a) equal to?

Correct Answer: (b) ab + bc + ca
Solution: