Question

The diameter of a spherical balloon increases from 14cm to 28 cm as air is being pumped into it find the ratio of surface aera of the baloons in two cases

Answer 1

d1-14cm
r1-7cm
area- 4πr²
=4x22/7x7
=88cm²
d2-28cm
r2-14cm
area=4πr²
=4x22/7x14
-352cm²
ration of surface area-88/352-1/4=1:4(Ans)