Question

The radii of two cylinders are in the ratio 3 : 5. If their heights are in the ratio 2 : 3, then the ratio of their curved surface areas is

Options

• 2 : 5

• 5 : 2

• 2 : 3

• 3 : 5

Answer 1

Given that

 `r_1 : r_2 = 3: 5`  and  `h_1 : h_2 = 2 : 3`

Then,

The ratio of C.S.A. of cylinders

`s_1 /s_2 = (2pir_1h_1) / (2pir_2h_2)`

`s_1/s_2 = (r_1/r_2) xx (h_1/h_2)`

      `= 3/5 xx 2/3`

 `s_1 /s_2 = 2/3`

`s_1 :s_2 = 2:5`