Lesson 1.8 PSI.notebook
October 04, 2011
Section 1­8
Problem­Solving Investigation (PSI)
Solve problems by working backward.
Examples:
1. Imagine that you have to catch a 1:30 P.M. flight to California. It takes 1 hour to check in at the airport and board the plane. It takes 1 ½ hours to drive to the airport and park the car. a. At what time should you get to the airport? Explain.
b. At what time should you leave your home to drive to the airport? Explain.
2. Wendy is meeting some friends for a movie and dinner. She needs to be finished with dinner by 7:30 P.M. to make it home by 8:00 P.M. The movie runs for 90 minutes, and she wants to have at least 1 hour for dinner. If it takes 20 minutes to get from the theater to the restaurant, what is the latest starting time she can choose for the movie she wants to see?
1
Lesson 1.8 PSI.notebook
October 04, 2011
3. During a hockey game, Brandon played 7 less minutes than Nick. Zach played 12 minutes more than Brandon. Hunter played twice as long as Zach. Hunter played for 44 minutes. How many minutes did Nick play in the hockey game?
4. In the morning, a delivery truck delivers 24 of its packages to a factory. It then goes to a distribution lot, where the remaining packages are separated into 4 equal groups and put on other trucks. There were 18 packages in each of the groups. How many packages were on the delivery truck to begin with?
2
Lesson 1.8 PSI.notebook
October 04, 2011
5. Zoe added 23 stamps to her collection. Three months later her collection had tripled in number to a total of 159 stamps. How many stamps did Zoe have to start her collection?
6. On Monday, Eliza read her book. On Tuesday, she read three times as long as she read on Monday. On Wednesday she read 20 minutes less than Tuesday. On Thursday she read for 20 minutes, which was half as long as she read on Wednesday. How many minutes did Eliza read over the 4­day period?
3
Lesson 1.8 PSI.notebook
October 04, 2011
Small Group Work
p. 63 #5, 6, 9 and 11
4