# 1.A cube has an edge measuring 8cm. Find the number of cubes of edges 2cm that can be cut of from it. 2.The area of the floor of a room is 67.5 sq m. Its volume is 270 m3 . Find the height of the room. 3.How many cubic blocks of wood of side 20 cm can be cut from a block of wood having dimensions of 2 m x 80 cm x 40 cm. 4. If the length of each edge of a cube is doubled how many times does its volume became? How many times does its surface area became?

2
by rahulmandal912

2016-01-17T10:17:30+05:30
The volume of big cube=8*8*8=512
Volume of small cube=2*2*2=8
Volume of big cube/volume of small cube =number of small cubes so.
512/8=64
So 64 cubes made from big cube
1m=100cm
2m=200cm
Volume of cubiod=200*80*40= 640000cm3
Volume of cube= 20*20*20=8000cm3
Divide volume if cubiod/volume of cube=num of cubes

640000/8000=80 cubes

So 80 cubes are made from cubiod

Let edge of cube = a
Volume of cube=a3
If side is doubled then side=2a
Volume with new side=8a3
So the volume became 8 times
Surface area =6*a2
New surface area =6*2a2
So surface area became 4 times

Thanks if i helped uuu
Jaspreet where is 2nd and and 4th and is wrong..
2nd and is not there and 4th and is wrong