Question

The ratio of the total surface area to the lateral surface area of a cylinder with base radius 80 cm and height 20 cm is

Options

• 2 : 1

• 3 : 1

• 4 : 1

• 5 : 1

Answer 1

5 : 1

Ratio of the total surface area to the lateral surface area `= "Total surface area"/"Latest surface area"`

`= (2pi("h"+"r"))/(2pi"rh")`

`= ("h" + "r")/"h"`

`= (20+80)/20`

`=100/20`

`= 5/1`

= 5 : 1

Hence, the required ratio is 5 : 1