Mensuration (Railway Maths) (Part – IX)

Total Questions: 50

31. The area of a rectangle with a length of 121 m is the same as that of a square with a side of 44 m. Find the width of the rectangle. [RRB NTPC 07/04/2021 (Evening) ]

Correct Answer: (d) 16 m
Solution:

32. A piece of wire is bent to form a circle with a radius of 70 cm. If the same piece of wire is bent to form a square, the length of the side of the square will be______. (Use π = 22/7) [RRB NTPC 08/04/2021 (Morning) ]

Correct Answer: (b) 110 cm
Solution:

33. If p is the length of a rectangle and its width is one-third of its length, then the area of the rectangle will be: [RRB NTPC 08/04/2021 (Morning)]

Correct Answer: (b) p² / 5
Solution:

Length of the rectangle = p
Breadth = p/3
Area of the rectangle = p × p/3 = p²/3

34. What is the ratio of the surface areas of two spheres, if their volumes are in the ratio 8 : 27? [RRB NTPC 08/04/2021 (Evening)]

Correct Answer: (b) 4 : 9
Solution:

35. A fence is constructed along the diagonal of a square field. What is the length of the fence (in km) if the area of the square field is 2 km²? [RRB NTPC 08/04/2021 (Evening)]

Correct Answer: (a) 2
Solution:

36. The radius of a sphere r is equal to the radius of the base of a right circular cylinder. The total volume of these two solids is 7/3​πr². If 'h' is the height of the cylinder. Find h/r. [RRB NTPC 23/07/2021 (Morning)]

Correct Answer: (c) 1
Solution:

37. If the volume of a cube is equal to the volume of a cuboid of dimensions 54 cm, 18 cm and 6 cm, then the length of the side of the cube is: [RRB NTPC 23/07/2021 (Evening)]

Correct Answer: (a) 18 cm
Solution:

Volume of cuboid = 54 × 18 × 6 = 5832
A/Q
Volume of cube = volume of cube
⇒ a³ = 5832 = 18³ ⇒ a = 18 cm

38. The radius and height of a solid cylinder are 6 m and 5 m. How many solid spheres of radius 3 m can be formed from that cylinder? [RRB NTPC 24/07/2021 (Morning)]

Correct Answer: (b) 5
Solution:

39. A rhombus has one diagonal double the other. If the area of the rhombus is K cm², then the length of its side will be: [RRB NTPC 24/07/2021 (Evening) ]

Correct Answer: (d)
Solution:

40. The area of a square field is 10,000 m². Find the perimeter of the square whose side is equal to the diagonal of the field. [RRB NTPC 26/07/2021 (Evening)]

Correct Answer: (b) 400√2 m
Solution: