In a hill station of state J & K where temperature in winter season falls to –20º C has resort for the tourist, who would like to enjoy the extreme cold environment.

Each room of resort is fitted with a separate heating device which makes the temperature of every element to 20ºC To maintain the temperature of room special kind of constant power of heater is fitted

Any tourist can stay inside the room or enjoy the cool environment of weather. The rent of room is calculated as a fixed charge of Rs. 1000 per day plus R = t + or Rs. 1000 whichever is maximum. where t is time of continuous stay inside the room in minute.

The given equation contains time because when tourist go for outside visit to resort he/she switched off all the heating devices. So, the room temperature goes down and when he/she re-enter in the room extra power is required to immediately raise the temperature to 20ºC.

So, for short time duration tourist has to pay more as compare with long stay inside the room.

When any tourist come in the resort it takes 10 minutes for the heating device to increase the temperature from –20ºC to 20ºC. Power loss to the surrounding varies as a function of temperature

P = kW, where T is in °