Question

find the volume of a sphere whose surface area is 154 cm

Answer 1

Surface area of sphere = 154 4πR^2 = 154 4*22/7*R^2 = 154 R^2 = 49/4 R = 7/2 Volume of sphere = 4/3 πR^3 = 4/3*22/7*7/2*7/2*7/2 = 539/3 = 179.67 cm

Answer 2

Surface area of sphere, 4πr^2 = 154
                               ⇒ r^2 = 154/4π
                                         = (154*7)/4*22 
                                         = 49/4
                                ⇒r =7/2 cm
Volume of sphere = 4/3π r^3 = 4/3*22/7*(7/2)^3  = 179.67 cm^3