Question

A wooden toy is in the form of a cone surmounted on a hemisphere. The diameter of the base of the cone is 16 cm and its height is 15 cm. Find the cost of painting the toy at Rs 7 per 100 cm².

Answer 1

In the given problem, we have a toy in the form of a cone surmounted on a hemisphere. So, let us first draw a diagram of the toy with the given dimensions.

So here,

Height of the cone = 15 cm

Diameter of the cone base and hemisphere = 16 cm

Therefore, radius of the cone base and hemisphere =

To find the lateral surface area of the cone, we first need to find the slant height of the cone, which is given by the following formula,

So, we get

Now, let us find the surface area of the toy first,

Total Surface area = lateral surface area of the cone + surface area of the hemisphere

So, the total surface area of the toy is 829.71 cm²

Now, the rate of painting the toy = Rs 7 per 100 cm²

= Rs per cm²

So, the cost of painting the given toy = total surface area x rate of painting

Therefore, the cost of painting the toy is