A sphere is cut into two equal halves and both the halves are painted

1.	A sphere is cut into two equal halves and both the halves are painted from all the sides. The radius of the sphere is r unit and the rate of painting is Rs. 8 per sq. unit. What is the total cost of painting the two halves of the sphere in rupees ?
Answer» Total surface area of the two halves = 3πr² + 3πr² = 6πr² sq units ∴ Cost of painting the two halves = 6πr² × Rs 8 = Rs 48 πr².

A sphere is cut into two equal halves and both the halves are painted from all the sides. The radius of the sphere is r unit and the rate of painting is Rs. 8 per sq. unit. What is the total cost of painting the two halves of the sphere in rupees ?

Answer»

Total surface area of the two halves = 3πr² + 3πr² = 6πr² sq units

∴ Cost of painting the two halves = 6πr² × Rs 8 = Rs 48 πr².