Mensuration (Railway Maths) (Part – IX)

Total Questions: 50

1. In a triangle, the ratio of the angles is 1 : 2 : 3. Find the difference between the greatest and the smallest angle. [RRB NTPC 21/03/2021 (Morning)]

Correct Answer: (a) 60°
Solution:

2. Find the number of lead balls of diameter 1 cm each that can be made from a lead sphere of diameter 16 cm. [RRB NTPC 21/03/2021 (Morning)]

Correct Answer: (c) 4096
Solution:

3. A square field of 2 sq km area is to be divided into two equal parts by a fence that coincides with a diagonal. Find the length of the fence. [RRB NTPC 21/03/2021 (Morning)]

Correct Answer: (b) 2 km
Solution:

Area of square = 2 𝑘m²
a² = 2 ⇒ a = √2
Diagonal of the square = a√2 = √2 × √2 = 2

4. Three cubes of a metal whose edges are 3, 4 and 5 cm respectively are melted and formed into a single cube. If there is no loss of metal in the process. Find the side of the new cube. [RRB NTPC 21/03/2021 (Evening)]

Correct Answer: (c) 6 cm
Solution:

Volume of all smaller cubes
= volume of bigger cube
⇒ 3³ + 4³ + 5³ = a³
⇒ 27 + 64 + 125 = a³
⇒ 216 = a³ ⇒ a = 6 cm

5. The side of an equilateral triangle is 10 cm. Find its altitude. [RRB NTPC 21/03/2021 (Evening)]

Correct Answer: (d) 5√3 cm
Solution:

Altitude = √3/2 × 10 = 5√3 cm

6. The curved surface area of a cylindrical pillar is 66 m² and its volume is 231 m³. Find the measure of its radius (π = 22/7) [RRB NTPC 27/03/2021 (Morning)]

Correct Answer: (b) 7 m
Solution:

7. If the radius of a cylinder is doubled and the height is halved, what will be the ratio of the new volume to the previous volume? [RRB NTPC 27/03/2021 (Morning)]

Correct Answer: (a) 2 : 1
Solution:

8. The two sides of a triangle measure 10 cm and 8 cm respectively. The area of the triangle is equal to 16√6 cm². Find the length of the third side, given that it is a rational number. [RRB NTPC 27/03/2021 (Evening) ]

Correct Answer: (c) 14 cm
Solution:

9. Find the answer of given question? [RRB NTPC 27/03/2021 (Evening) ]

Correct Answer: (a) 27.5 cm
Solution:

10. The altitude drawn to the base of an isosceles triangle is 12 cm and the perimeter is 36 cm. Find the area of the triangle. [RRB NTPC 27/03/2021 (Evening) ]

Correct Answer: (b) 60 cm²
Solution: