A pan filled with hot food cools from 94∘C to 86∘C in 2 minutes. When the room temperature is 20∘C. How long will it cool from 74∘C to 66∘C?
A body takes 4 minutes to cool from 100o C to 70o C. To cool from 70o C to 40o C it will take (room temperature is 15o C )