A container, opened from the top and made of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper ends as 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. Also, find the cost of metal sheet used to make the container, if it costs Rs 8 per 100
. (Take
).
Solution:
Height of frustum of cone
cm
Radius of lower end
cm
Radius of upper end
cm
Volume of container
=10.44992 litres
Cost of milk to fill the container at the rate of Rs 20 per litre
Rs 209
Slant height of frustum of cone
cm
Total surface area of frustum
100
of metal sheet costs = Rs 8
1
of metal sheet would cost = Rs
1959.36
of metal sheet would cost
Rs 156.75
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