A farmer wants to paint the outside of his grain bin. The grain bin has a cylindrical base topped with a cone.

a. If the diameter of the grain bin's is 15m, the height of the cylindrical portion of the grain bin is 20 m, and the slant height of the cone roof is 8 m, determine the SA of the grain bin requiring paint, to the nearest hundredth of a square metre.

b. The farmer intends to purchase large cans of paint that each cover 400 ft² of surafce area. If 1 m² = 10.764 ft^2, estimate the number of cans needed to paint the silo