Bell Work: What is the volume of 2 liters of water?

Answer: 2000 cm 3

Lesson 105: Compound Average and Rate Problems

In this lesson we will solve problems that include more than one average or rate.

Example: Blanca bought 200 shares of XYZ stock at an average price of $54 per share. Later she bought 100 more shares at $60 per share. What was the average price per share Blanca paid for all 300 shares of XYZ?

Answer: 200 shares at $54 = $10,800 +100 shares at $60 = $6,000 300 shares at x = $16,800 x = $56

Example: After three games of bowling, Gabe’s average score was 88 Example: After three games of bowling, Gabe’s average score was 88. what score does Gabe need to average in his next two games to raise his average to 90?

Answer: 3 x 88 = 264 5 x 90 = 450 450 – 264 = 186 186/ 2 = 93 93 on his next two games.

Many rate problems can be solved like average problems as we see in the next example.

Example: Because of the heavy traffic, the 120- mile trip to San Diego took 3 hours. The traffic was lighter on the return trip, which took 2 hours. Find the average speed for each trip and for the round trip.

Answer: 120miles/3hours = 40mph 120miles/2hours = 60mph 120 + 120/3 + 2 = 240miles/5hours 48mph

HW: Lesson 105 #1-25