Mensuration (C10)

A man donates 10 aluminum buckets to an orphanage. A bucket made of aluminum is of height 20 cm and has its upper and lowest ends of radius 36 cm and 21 cm respectively. Find the cost of preparing 10 buckets if the cost of aluminum sheet is Rs. 42 per 100 cm2.

Answer

Surface area of bucket = π(r1 + r2)l + πr12

l = √[h2 + (r2 - r1)2]

= √625 = 25 cm

∴ Surface area of 1 bucket = 22/7 × 1866 cm2

Surface area of 10 buckets = 22/7 × 18660 cm2

Cost of aluminium sheet = Rs. 24631.20