Surface area of a sphere is 2464 cm2. If its radius is doubled, then the surface area of the new sphere will be  Choose the correct choice from the following choices: A) 4920 cm 2 B) 4727 cm 2 C) 9856 cm 2 D) 19712 cm 2 E) none

Rationale: sol . let the original radius be r . then , original surface area = 4 π r 2 = 2464 cm 2 ( given ) . new radius = 2 r . ∴ new surface area = 4 π ( 2 r ) 2 = 4 x 4 π r 2 = ( 4 x 2464 ) cm 2 = 9856 cm 2 answer c
Answer: C