Mensuration (Railway Maths) (Part – VI)

Total Questions: 50

1. If the area of a circle is 154 cm² then the circumference of the circle is ? [RRB NTPC 04/01/2021 (Morning) ]

Correct Answer: (a) 44 cm
Solution:

2. How many straight lines does a cuboid have ? [RRB NTPC 04/01/2021 (Evening) ]

Correct Answer: (b) 12
Solution:

3. What is the total surface area of the visible faces in the given figure? [RRB NTPC 05/01/2021 (Morning) ]

Correct Answer: (a) 384 cm²
Solution:


From the above figure, we can get,
DE = GF = (20 - 7) = 13; DG = IJ = 8;
HL = CG = (15 - 8) = 7,
So, the total surface area of the visible faces in the given figure →
= Area of the rectangles (ABCD + DEFG + BCLK + CGHL + GHIF + EFIJ)
= 105 + 104 + 35 + 35 + 65 + 40 = 384
So, the total surface area of the visible faces in the given figure is 384 cm².

4. If the dimensions of a room are 2 m, 3 m and 4 m, then how many cubes of size 1/2 m × 1/3 m × 1/4 m can be placed in the same room? [RRB NTPC 05/01/2021 (Morning)]

Correct Answer: (c) 576
Solution:

5. A cylinder and a cone are of the same base radius and the same height. Find the ratio of the volume of the cylinder to that of the cone. [RRB NTPC 05/01/2021 (Evening)]

Correct Answer: (a) 3 : 1
Solution:

6. If the radius of a sphere is doubled, what will be the ratio of the volume of the new sphere to that of the original sphere? [RRB NTPC 05/01/2021 (Evening)]

Correct Answer: (a) 8 : 1
Solution:

7. A sector is cut off from a circle of radius 21 cm. The angle of the sector is 40 degrees. Find the area of the sector in square cm? [RRB NTPC 07/01/2021 (Morning) ]

Correct Answer: (b) 154
Solution:

8. When the side of an equilateral triangle is made three times the original side, the area of the new equilateral will become: [RRB NTPC 07/01/2021 (Morning) ]

Correct Answer: (c) 9 times of the original area
Solution:

9. What is the area of the compound shape? [RRB NTPC 07/01/2021 (Evening) ]

Correct Answer: (a) 135 square units
Solution:

10. The floor of a hall measuring 16 meters in length and 12 meters in width is to be paved with square tiles. If the least number of tiles are to be used, then what is the length of each square tile? [RRB NTPC 08/01/2021 (Morning) ]

Correct Answer: (d) 4 meters
Solution:

Tiles are square tiles and least no. of tiles is used.
Therefore, length of each square tiles
= HCF of (12 and 16) = 4 meters