A conical tent was erected by army at a base camp with height 3 m and base diameter 8 m. Find :
(i) The cost of canvas required for making the tent, if the canvas cost Rs. 70 per 1 sq. m.
(ii) If every person requires 3.5 m2 air, how many persons can be seated in that tent.
Diameter of the tent =8 m
r=d2=82=4 m
Height =3 m
Slant height (l)=√h2+r2
=√32+42
=√25=5 m
Therefore, curved surface area of tent =πrl
=227×4×5=4407 m2
Volume of the cone =13πr2h
=13×227×4×4×3
=3527 m3
(i) Cost of canvas required for the tent
= C.S.A. × Unit cost
=4407×70
= Rs. 4400
(ii) Number of persons can be seated in the tent
=Volume of conical tentAir required for each
=3527÷3.5
=3527×13.5=14.36
=14 men (approx.)