Question

The ratio of lateral surface area to the total surface area of a cylinder with base diameter 1.6 m and height 20 cm is

Options

• 1 : 7

• 1 : 5

• 7 : 1

• 8 : 1

Answer 1

`r= (1.6m)/2`

`=160/2`

`=80 cm`

`h = 20 cm`

The ratio of lateral surface to the total surface area of cylinder

`s_1/s_2 = (2pirh)/(2pir (h+r))`

`s_1/s_2= h /(h + r)`

      ` = 20/(20 + 80)`

`s_1 / s_2 = 20/100`

      `= 1/5`

`s_1 : s_2 = 1:5`