The radius and height of a right angle circular cone are in the ratio 1:(2.4). If its curved surface area is 2502.5 cm2, then what is its volume?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 13475 cm3
Let the radius = r and height = h
r : h = 1 : 2.4
so, r = k and h = 2.4k
l = (k2 + (2.4k)2)½ = 2.6k
the curved surface area of the cylinder = 2502.5 cm2
so, the curved surafce area of the cone = ᴨrl = 2502.5 cm2
ᴨ × k × 2.6k = 2502.5 cm2
⇒ k = 17.5 cm
volume of the cone = (ᴨ × r2 × h)/3 = (3.14 × k2 × 2.4k)/3 = 13475 cm3