Question

A container opened from the top is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends are 8 cm and 20 cm
respectively. Find the cost of the milk which can completely fill the container at the rate of Rs. 20 per litre. [Take a = 3.14]​

Answer 1

Answer:

₹209 ( approx )

Step-by-step explanation:

volume of container = volume of frustum cone

volume of container = 1/3 πh ( R² + r² + R×r)

here,

h = 16cm

R = 8cm

r = 20cm

substitute in the formula, we get

10445.76cm³

10445.76/1000        (∵ 1000cm³= 1 litre

10.44576 litres             10445.76cm3=10445.76/1000 litres)

cost of milk per litre = ₹20

cost of milk for 10.44576 litres = 10.44576×20

                                                  = 208.91 = ₹209 ( approx)