Question

A container made of a metal sheet open at the top is of the form of frustum of cone whose height is 16cm and the radii of its lower and upper circular edges are 8cm and 20cm respectively. find 1. the cost of metal sheet used to make the container if it costs ₹10per 100cm^2
2.the cost of milk at the rate of ₹35 per litre which can fill it completely ​

Answer 1

Answer:

Radius r1 of upper end of the container=20cm

Radius r2 of lower end of the container=8cm

Height h of the container=16cm

Slant height l of the frustrum=(r1−r2)2+h2

                                  =(20−8)2+162=144+256=20cm

Capacity of container=Volume of the frustrum

=31πh(r12+r22+r1r2)

=31×3.14×16(202+82+20×8)

=31×3.14×16(400+64+160)

=31×3.14×16×624

=