SOLUTION: A salesman sold 20 cars in the month of July, and 40 cars the month of August. What is the percent increase in the number of cars the salesman sold?

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Question 5405: A salesman sold 20 cars in the month of July, and 40 cars the month of August. What is the percent increase in the number of cars the salesman sold?


Answer by Abbey(339) About Me  (Show Source):
You can put this solution on YOUR website!
Use a proportionality:
%2840+cars%29%2F%2820+cars%29+=+%28what+percent%29%2F%28100+percent%29
40%2F20+=+x%2F100
cross multiply:
20x=4000
Divide both sides by 20
x=200%25
But we want to know the amount of increase, so if 20 cars is 100%, then 40-20 cars = 200%-100%, or a 100% increase.