1. Objective: Review. Warm up 1.Mary can fill a pool carrying buckets of water in 30 minutes. Sue can do the same in 45 minutes. Tony can do the same job in 1.5 hours. How quickly can all three fill the pool together?

2. A census taker approaches a house and asks the woman who answers the door "How many children do you have, and what are their ages?" Woman: "I have three children, the product of their ages are 36, and the sum of their ages are equal to the address of the house next door." The census taker walks next door, comes back and says "I need more information." The woman replies "I have to go, my oldest child is sleeping upstairs." Census taker: "Thank you, I now have everything I need.”

3. 3. A scientist decided to determine how bacteria were thriving in a petri dish in a very cold freezer. After 2 hours there were 600 live bacteria ; after 6 hours there were only 100 live bacteria in the petri dish. Determine the average rate of change of the bacteria with respect to time from 2 to 6 hours.