Question

The radius of a spherical balloon increases from 7cm to 14cm as air is being pumped into it. Find the ratio of surface areas of the balloon in two cases.​

Answer 1

Answer:

Ratio of surface area =2464616=41.

This answer us 100% right

Answer 2

$\huge \dag \: { \purple{ \boxed{ \underline{ \sf{Answer}}}}}$

R = radius of ballon = 7cm

r = radius of pumped ballon = 14cm

surface area of sphere before inflated / urface area of spherical ballon after inflated

=4×(22/7)×R×R / 4 × (22/7) × r×r

= R×R/r×r

=7×7/14×14

= 49 / 196

= 1:4