Question

A metal container ,open from the top ,is in the shape of a frustum of a cone of height 21cm with radii of its lower and upper circular ends as 8 cm and 20 cm respectively .Find the cost of milk which can completely fill the container at the rate of rs.50 per

Answer 1

Answer:

Given,

Height of milk container (h) = 21 cm,

 Radius of  lower finish of milk container (r) = 8cm

 Radius of higher finish of milk container (R) = 20 cm

Volume of frustum = $\pi$ /3 H (R^2 + r^2 + R×r)

=> = $\pi$ /3 × 21 (20$^{2}$ + 8$^{2}$ + 20×8)

=> $\pi$ /3 × 21 (400+62+160)

=> 22× 624

=> 13728$cm^{2}$

∵ 1$cm^{3}$= 1/1000 liter

∴ 13728 $cm^{3}$ =13.728 liter

Rate of milk = RS 50 per liter

Total  cost = 13.728×50

=> Total cost of milk = RS 686.4

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@GauravSaxena01