If the both the radius and height of a right circular cone are increased by 20%, its volume will be increased by:
72.8%
Let the original radius and height of the cone be `r' and `h' respectively.
Then, original volume =13πr2h.
New radius = 120100r=65r,
New height = 65h
New volume =13π×(65r)2×(65h)=216125×13πr2h
Increase in volume =91125×13πr2h
∴Increase % = [91125×13πr2h13πr2h×100]
= 72.8%