Mensuration (Railway Maths) (Part – VII)

Total Questions: 50

1. The ratio of the area of an equilateral triangle of side x to the area of a square of side x is ? [RRB NTPC 25/01/2021 (Evening) ]

Correct Answer: (d) √3 : 4
Solution:

2. A rectangular field is to be fenced on three sides leaving a side of 30 ft. uncovered. If the area of the field is 690 sq. ft how many feet of fencing will be required ? [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (c) 76
Solution:

If the length of one side is 30 ft and the area is 690 ft 2
⇒ Length of another side = 23ft
Now, length of fencing required for the three sides
= 23 + 23 + 30 = 76 ft

3. The ratio of the length to the breadth of a rectangular field is 7 : 6. If the breadth is 35 m less than the length, then the perimeter of the field is : [RRB NTPC 27/01/2021 (Morning)]

Correct Answer: (a) 910 m
Solution:

Let length and breadth be 7x and 6x respectively.
ATQ, 7x - 6x = 35 ⇒ x = 35
Perimeter = 2(7x + 6x) = 26x
= 26 × 35 = 910 m

4. Find the cost of fencing a square plot of land with an area of 11025 m², at the rate of Rs. 85 per metre. [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (d) Rs. 35,700
Solution:

5. A cord is in the form of a square enclosing an area of 22 cm². If the same cord is formed into a circle, then find the area enclosed by the circle. [Take π = 22/7] [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (c) 28 cm²
Solution:

6. If one envelope requires a paper size of 18 cm × 12 cm, then how many envelopes can be made out of a sheet of paper of size 72 cm × 48 cm? [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (a) 16
Solution:

7. The area of trapezium is 540 m². If the parallel sides are 30 m and 24 m in length, then find the distance between them. [RRB NTPC 27/01/2021 (Evening)]

Correct Answer: (a) 20 m
Solution:

Area of the trapezium = 1/2 (sum of parallel sides) × (distance between both parallel sides)
⇒ 1/2 (30 + 24) × d = 540
⇒ 27d = 540 ⇒ d = 20 m

8. Find the area of a trapezium whose parallel sides are 10 cm and 20 cm and non-parallel sides are equal to 10 cm. [RRB NTPC 28/01/2021 (Morning)]

Correct Answer: (b) 75√3 cm²
Solution:

9. The radius of a 80 cm wide road roller is 77cm. Find the number of revolutions that the roller will take tocover an area of 96.8 m². [Take π = 22/7] [RRB NTPC 28/01/2021(Morning) ]

Correct Answer: (a) 25
Solution:

10. If the total surface area of a cube is 864 m², then its volume is: [RRB NTPC 28/01/2021 (Evening) ]

Correct Answer: (c) 1726 m³
Solution: