Three solid cubes of sides 1 cm, 6 cm and 8 cm are melted to form a new Cube. Find the surface area of the cube so formed.
486 cm2.
488cm2.
479 cm2.
445 cm2.
A. 486 cm2.
Volume of new cube = (13 + 63 + 83) cm+ = 729 cm3.
Edge of new cube = 3Ö729 cm = 9 cm.
Surface area of the new cube = (6 x 9 x 9) cm2 = 486 cm2.
20 cm
21 cm
23 cm
24 cm
The dimensions of an open box are 50 cm, 40 cm and 23 cm. Its thickness is 2 cm. If 1 cubic cm of metal used in the box weighs 0.5 gms, find the weight of the box.
8 kg
8.04 kg
8.5 kg
8.004 kg
The volume of a wall, 5 times as high as it is broad and 8 times as long as it is high, is 12.8 cu. meters. Find the breadth of the wall.
30 cm
40 cm
50 cm
55 cm
Two cubes have their volumes in the ratio 1 : 27. Find the ratio of their surface areas.
1:2
2:3
2:5
1:9
Water flows into a tank 200 m x 160 m througb a rectangular pipe of 1.5m x 1.25 m @ 20 kmph . In what time (in minutes) will the water rise by metres?
50 min
55 min
90 min
96 min
40,000
42,000
45,000
47,000
4012 cm3.
4711 cm3.
4812 cm3.
4913 cm3.
Three solid cubes of sides 1 cm, 6 cm and 8 cm are melted to form a new Cube. Find the surface area of the cube so formed.
486 cm2.
488cm2.
479 cm2.
445 cm2.
How many iron rods, each of length 7 m and diameter 2 cm can be made out of 0.88 cubic meter of iron?
200
330
400
450
10 cm
10.25 cm
11 cm
11.25 cm
20
30
40
50
345 cm2
868 cm2
876 cm2
678 cm2