The curved surface area of one cone is twice that of the other while the slant height of the latter is twice that of the former. The ratio of their radii is

Options

A. `2 : 1`
B. `4 : 1`
C. `8 : 1`
D. `1 : 1`

Answer

B

Explanation

Let their slant heights be l and 2l and their radii be `R_(1) and R_(2)`. Then,
`(piR_(1)l)/(pi R_(2)(2l)) = (2)/(1) rArr (R_(1))/(R_(2)) = (4)/(1) = 4 : 1`