Title: Lesson 10-4
Author: mark_cameron
Last saved by: The McGraw-Hill Companies
Company: McGraw-Hill

Lesson 8-5 Problem-Solving Investigation

Guess and Check

CONCERTS   300 tickets were sold to a local rock festival. If you bought tickets a year in advance they were 60 dollars. If you bought them anytime after that, tickets were 80 dollars. The total revenue for ticket sales was $20,000. How many of each type of ticket were sold?

Understand	The total number of tickets sold was 300. The total revenue from ticket sales was $20,000. The cost of the different types of tickets was $60 and $80. 

Plan 	Use a systematic guess and check to find the correct number of each type of ticket sold. 

Solve		150 · 60 + 150 · 80 = 21,000		Too high 
		50 · 60 + 250 · 80 = 23,000		Too high
		250 · 60 + 50 · 80 = 19,000		Too low
		200 · 60 + 100 · 80 = 20,000		Correct 

So, there were 200 $60 tickets sold and 100 $80 tickets sold. 

Check	The sum of 200 advanced tickets and 100 regular tickets is 300.  Since 60(200) + 80(100) = 20,000, the guess is correct.