Question 17.

Let the base radius be 3r.

Height of upper cone is 9 so, by symmetry radius of upper cone will be r.

Volume of frustum=$\fracπ3(9r^2⋅27−r^2⋅9)$

Volume of upper cone = $\fracπ3⋅r^2⋅9$

Difference= $\fracπ3⋅9⋅r^2⋅25 = 225 = \frac{\pi}{3} ⋅ r^2 = 1$

Volume of larger cone = $\fracπ3⋅9r^2⋅27=243$