Question

the radius of a Sphere is increased by 140%.By what percent Will it's volume increased.​

Answer 1

Volume of a sphere of radius 'r' = 4/3 π r²

New radius = 140/1000r = 7/50r

Hence,

volume of the new sphere = 4/3π (7/50r)²

                                            = 4/3 πr² × 49/2500

increase in volume = new volume/old volume × 100

                                = (4/3πr² × 49/2500) / 4/3πr² × 100

                                = 49/2500 × 100

                                = 1.96 %

hope this helps