(a) D + h = 42 m. Quantity 1 : 7x = 42 x = 6 r = 12 m h = 18 m Curved surface area of cylinder = 2π× 18 × 12 =2π×216m2 Quantity 2: h = 15m Radius =
42−15
2
= 13.5 m Curved surface area of cylinder = 2π × 13.5 × 15 =2π×202.5m2 Quantity 1 > Quantity 2