The ratio of the height and the diameter of a right…

The ratio of the height and the diameter of a right circular cone is 6 : 5 and its volume is $\frac{2200}{7}$ cm³. What is its slant height?

Show answer & explanation

Correct answer: B

Explanation

The correct answer is option 2 i.e. 13 cm

h : 2r = 6 : 5

Let h = 6x and 2r = 5x.

Volume of cone = 2200/7

1/3 × 22/7 × 5x/2 × 5x/2 × 6x = 2200/7

x³ = 8

x = 2 cm

h = 6 × 2 = 12

r = 5 × 2/1 = 5

Slant height = $\sqrt{12^2 + 5^2}$ = 13 cm.

SSC CGL 2020 PYQ — Question 81