A conical tent is to accommodate 11 persons. Each person must have 4 square metres of the space on the ground and 20 m3 of air to breathe. Find the height of the cone.
15 m
Required area of the base of cone = 11×4=44 m2
and required volume of cone =11×20=220 m3
⇒13(πr2h)=220⇒13×44×h=220⇒h=220×344=15 m
∴ Height of cone = 15 m