11.
Calculate the number of bricks, each measuring 25 cm x 15 cm x 8 cm, required to construct a wall of dimension 19m x 4m x 5m, when 10% of its volume is occupied by mortar.
- A.4000
- C.7000
- B.8000
- D.6000
- Answer & Explanation
- Report
Answer : [D]
Explanation :
Explanation :
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12.
The volume of cube is 729 cm3. The total surface area of the cube is
- A.216 cm2
- C.486 cm2
- B.384 cm2
- D.512 cm2
- Answer & Explanation
- Report
Answer : [C]
Explanation :
Explanation :
| Length of the cube = (729)1/3 = 9 | |
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13.
A cube of edge 3 cm of iron weighs 12 gm. What is the weight of a similar cube of iron whose edge is 12 cm?
- A.768 gm
- C.964 gm
- B.678 gm
- D.864 gm
- Answer & Explanation
- Report
Answer : [A]
Explanation :
Explanation :
| Ratio of the edge of cubes = 3 : 12 = 1 : 4 |
| Ratio of their volumes = 13 : 43 = 1 : 64 |
| Because volume of the new cube is 64 times the volume of the first cube, the weight of the new cube is also 64 times the weight of the first cube. |
| Weight of the new cube = 64 x 12 gm = 768 gm |
14.
A cubic metre of silver weighing 900 kg is rolled into a square bar 16 m long. Find the weight of an exact cube cut off from it.
- A.14 kg 62
- C.10 kg
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- B.30 kg
- D.7 kg 50 gm
- Answer & Explanation
- Report
Answer : [A]
Explanation :
Explanation :
| Let x be the side of the base of the square bar 16 m long. | ||||||||||||||||
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| Now, 1 m3 weighs 900 kg | ||||||||||||||||
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