Question 4324: Story Problem:
Justin purchased some 23 cent stamps and some 37 cent stamps. He bought a total of 80 stamps for a total cost of less than $25. What is the maximum number of 37 cent stamps that Justin could have purchased?
Please show the set up & formula for solving this. Thank You!
Answer by rapaljer(4671)   (Show Source):
You can put this solution on YOUR website! This is a good problem to write two equations in two variables.
Let x = number of 23 cent stamps
y = number of 37 cent stamps
Total of the stamps is 80, so x + y = 80.
Value of the stamps is $25 or 2500 cents, so 23x + 37y = 2500
To eliminate the x, multiply both sides of the first equation by -23.
-23x - 23y = -23(80)= -1840
+23x + 37y = 2500
Add the equations together
14y = 660
Divide both sides by 14, giving a value of y that does not come out even.
y = 660/14 = 47.142857. . .
This means that the MAXIMUM number of 37 cent stamps = 47 FINAL ANSWER!!
As a check, subtract 80 - 47 = 33 of the 23 cent stamps. The total value of the stamps is
47(37) = $17.39
33(33) = $ 7.59
Total = $24.98 Only $.02 left out of the $25.
R^2 at SCC
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