Question

A cup of coffee cools from 90°C to 80°C in t minutes, when the room temperature is 20°C. The time taken for a similar cup of coffee to cool from 80°C to 60°C at a room temperature same at 20°C is ______

Options

• `5/13"t"`

• `13/10"t"`

• `13/5"t"`

• `10/13"t"`

Answer 1

A cup of coffee cools from 90°C to 80°C in t minutes, when the room temperature is 20°C. The time taken for a similar cup of coffee to cool from 80°C to 60°C at room temperature same at 20°C is `underline(13/5"t")`.