A 5-m-wide cloth is used to make a conical tent of base diameter 14 m and height 24 m. Find the cost of cloth used at the rate of Rs 25 per metre.
Width of cloth used = 5 m
Diameter of conical tent to be made = 14 m
Let the radius of the conical tent be r m
Radius of conical tent = r = diameter ÷ 2 = 14/2 m = 7 m
Height of conical tent = h = 24 m
Let the slant height of conical tent be l
So,
⇒ m2
⇒ l = 25 m
Area of cloth required to make a conical tent = Curved Surface area of conical tent
= πrl
= 22/7 × 7 × 25 m2
= 550 m2
Length of cloth used = Area of cloth required ÷ width of cloth
= 550/5 m
= 110 m
∴ Length of cloth used = 110 m
Cost of cloth used = Rs 25 per meter
Total Cost of cloth required to make a conical tent = 110 × Rs 25
= Rs 2750
∴ Total cost of cloth required to make a conical tent = Rs 2750