(a) Two teachers enter the teacher's lounge which is kept at a constant temperature of 70 degrees Celsius. They each pour themselves a cup of coffee at precisely the same time. The temperature of the coffee is 220 degrees Celsius. Teacher 1 adds cream (at room temperature) to her coffee. After 15 minutes Teacher 2 adds cream (at room temperature) to her coffee. Use Newton's Law of Cooling to model this situation and predict whose coffee (ii) is hotter. Would your answer change if the cream was kept in the refrigerator at 50 degrees Celsius until used? How so? dy +(1-x)y e; y(1)=0 (b) Solve dx (10 marks) [10 marks)