Question

A milk container is made of metal sheet in the shape of frustum of a cone whose volume is 10459 3/7cm³. The radii of its lower and upper circular ends are 8cm and 20cm. find the cost of metal sheet used in making container at rate of  Rs 1.4 per cm² ?

Answer 1

Given lower end radius of bucket (r₁) = 8cm

Upper end radius of bucket

Let height of bucket be ‘h’

Height of frustum cone (h) = 16cm 

Let slant height of frustum cone be ‘l’