UPSC 2016 CDS II Math Paper

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