UPSC CDS Math Volume and Surface Area Questions

Let r1 and r2 be the radii of the bottom and top circular ends of the frustum of the cone, respectively.
Here, r1=2 cm and r2=9 cm
Height of the frustum of the cone = h = 24 cm
Capacity of the glass =πxcm3
∴

1

3

πh(r12+r1r2+r22)=πx
⇒

1

3

×24×(4+18+81)=x
⇒x=824