Question

The radius of spherical balloon increases from 7 cm to 14 cm when air is pumped into it. Find the ratio of surface areas of original balloon to inflated. (3M)

Answer 1

ans is 1/4

r

1

=7cm

r

2

=14cm,

Required ratio =

4πr

2

2

4πr

1

2

=(

r

2

r

1

)

2

=(

14

7

)

2

=

4

1