1. A cup of coffee bought from Kalayaan, Laguna has a temperature of 200F and is placed in a room that has a temperature of 70F. After 10 minutes, the temperature of the coffee is 150F. Find the temperature of the coffee after 15 minutes. When will the coffee have cooled to 100F? Express your answer in seconds, minutes, and hours. 2. A thermometer reading 3 75F is taken out in a reefer van where the temperature is 20F. The reading is 30F, 4 minutes later. Find the thermometer reading 7 minutes after the thermometer was brought outside and the time taken for the reading to drop from 75F to within a half degree of the air temperature. 3. The population of a certain country doubles in 50 years. When will be the population be tripled? Assume a law of growth to hold. 4. The population growth of a certain colony of mosquitoes follows the uninhabited growth equation. If there are 100 mosquitoes initially, and there are 2500 mosquitoes after 24 hours. What is the size of the mosquito population after 3 days