If the radius of a sphere is increased by 20 percent, by what percentage will its volume increase?
Show answer & explanation
Correct answer: C
Explanation
Increase in radius = 20%
Volume of sphere = r³
New radius = 1.2r
New volume = (1.2r)³ = 1.728 r³
Increase in volume= 1.728 − 1= 0.728
Percentage increase = 0.728 × 100 = 72.8%