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

Total Questions: 100

51. (Questions 51-53) Consider the following for the next three questions that follow.

ABC is a triangle with sides AB = 6 cm, BC = 10 cm and CA = 8 cm. With vertices A B, and C as centres, three circles are drawn each touching the other two externally.

What is the sum of the radii of the circles?

Correct Answer: (c) 12 cm
Solution:In ∆ABC it is given that

52. What is the length of the altitude of the triangle drawn from vertex A on BC ?

Correct Answer: (d) 4.8 cm
Solution:In ∆ABC it is given that


53. If P, Q and R are the areas of sectors at A B, and C within the triangle respectively, then which of the following is/are correct

1. P = π cm²
2. 9Q + 4R + = 36π cm²

Select the correct answer using the code given below:

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

54. (Questions 54 and 55) Consider the following next two questions that follow.

ABC is triangle in which AB = AC and D is any point on BC.

Which one of the following is correct?

Correct Answer: (b) AC²- AD² = BD × CD
Solution:

55. If AD = 5cm BD = 4cm and CD = 6 cm, then what is AB equal to ?

Correct Answer: (a) 7 cm
Solution:

56. (Questions 56-58) Consider the following for next three questions that follow.

ABC is a triangle with AB = 1.6cm, BC = 6.3cm and CA = 6.5cm . Let P and Q be the mid-points of AB and BC respectively.

What is AB² + 4 BQ² equal to ?

Correct Answer: (b) 42.25 cm²
Solution:



57. What is AQ² + CP² equal to?

Correct Answer: (c) 1.25 AC²
Solution:

58. What is 4(CP² - AQ²) equal to?

Correct Answer: (b) 111.39 cm²
Solution:

59. (Questions 59 and 60) Consider the following for the next two questions that follows.

AB is a diameter of a circle with centre O. Radius OP is perpendicular to AB. Let Q be any point on are PB.

What is ∠BAP equal to ?

Correct Answer: (c) 45°
Solution:

60. What is ∠AQP equal to?

Correct Answer: (c) 45°
Solution: