UPSC CDS Math Volume and Surface Area Questions

We have,
Diameter of base = 6 cm and diameter of top of the bucket = 12 cm
Then radius of base (l1)=3cm and radius of top of the bucket (r2)=6cm
And, height of the bucket (h)=7cm
Then capacity or volume of the bucket =‌

1

3

πh(r12+r22+r1r2)
=‌

1

3

π×7(32+62+3×6)
=‌

1

3

×‌

22

7

×7×63
=462cm3