If the radius of sphere is decreased by 10 percent, then volume of sphere will be decreased by what percentage ?

27.1 percent

The radius of sphere is decreased by 10 percent

               Original   :    New

Radius            10    :      9

Initial Volume = \(\frac{4}{3}\) × \(\pi \) × r × r × r

 = \(\frac{4}{3}\) × \(\pi \) × 10 × 10 ×10

= \(\frac{4}{3}\) × 1000

Final Volume = \(\frac{4}{3}\) × \(\pi \) × r × r × r

 = \(\frac{4}{3}\)  × \(\pi \) × 9 × 9 × 9

= \(\frac{4}{3}\)  × 729

Difference =  \(\frac{4}{3}\)  × (1000 - 729)

Required percentage = \(\frac{271}{1000}\) × 100 = 27.1%