Question

the radius of a sphere is 14cm .To paint the surface of the sphere at 2 paise per 1 sq cm ,how much will it cost?​

Answer 1

Given data :-

—› Radius of sphere ( r ) = 14 cm

—› To paint the surface of the sphere at 2 paise per 1 cm² .

Solution:-

To find surface area of sphere we use formula :-

—› Surface area of sphere = 4πr²

—› Surface area of sphere = 4 × 22/7 × 14

—› Surface are of sphere = 4 × 22 × 2

—› Surface are of sphere = 88 × 2

—› Surface are of sphere = 176 cm²

—› Cost to paint surface of sphere

= [Surface are of sphere] × [cost to paint]

—› Cost to paint surface of sphere

= 176 × 2

—› Cost to paint surface of sphere

= 352 paise = Rs 3.52

Hence, Cost to paint surface of sphere is 352 paise or Rs 3.52

{ Note :- if sphere need to paint from inner h outer side then cist will be double 704 paise or Rs 7.04 }