Question

A METAL BALL WITH A RADIUS OF 6 CM IS MELTED TO FORM SOME SMALL BALLS EACH WITH RADIUS OF 1.5 CM.FIND THE NUMBER OF SMALL BALLS THAT CAN BE FORMED.

Answer 1

Volume of large ball = 4/3 * pi * 6^3

volume of a smaller ball = 4/3 * pi * 1.5^3

Dividing the volume of large by volume of smaller = 6^3 / 1.5^3

= 64 balls ( answer)

Answer 2

Volume of a sphere = 4/3 * pi * r^3
Volume of big sphere = 4/3 *22/7*6*6*6
Volume of small sphere = 4/3*22/7*1.5*1.5*1.5


Therefore number of small balls = (Volume of big sphere)/(Volume of small sphere)
= (4/3*22/7*6*6*6)/(4/3*22/7*1.5*1.5*1.5) [4/3 & 22/7 get cancelled]



Therefore we are left with (6*6*6)/(1.5*1.5*1.5)
=4*4*4
=64