Question

The radii of two solid cones are equal and their slant heights are in the ratio 7 : 4. The ratio between their curved surface areas is:

Options

• 4 : 7

• 7 : 4

• 16 : 49

• 49: 16

Answer 1

7 : 4

Explanation:

Let radii of both the cones be r units each.

Let slant height of two cones be l₁ and l₂.

Curved surface area of first cone = πrl₁

Curved surface area of second cone = πrl₂

`("CSA of 1st cone")/("CSA of 2nd cone​") = (​πrl_1)/(πrl_2​​) = (l_1​​)/(l_2​) = 7/4​ = 7 : 4.`