The rate of cooling of an object is proportional to the temperature difference between the object and its surroundings.

A drink with 72 degrees is placed in a refridgerator with 44 degrees. After half an hour, the drink is at 61 degrees.

• What is the temperature of the drink after t hours?
• What is the temperature of the drink after one hour?
• When is the temperature of the drink equal to 50 degrees?