SOLUTION: Allen bought 20 stamps at the post office in 37 cent and 20 cent denominations. If the total cost of the stamps was $7.06 how many 37 cent stamps did Allen buy? No book. Thanks so

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Question 53098: Allen bought 20 stamps at the post office in 37 cent and 20 cent denominations. If the total cost of the stamps was $7.06 how many 37 cent stamps did Allen buy? No book. Thanks so much!
Answer by funmath(2933) About Me  (Show Source):
You can put this solution on YOUR website!
Let the number of 37 cent stamps=x
Let the rest of the 20 stamps be the 20 cent stamps=20-x
The cost of 37 cent stamps =.37x
The cost of 20 cent stamps=.20(20-x)
The total cost =7.06
.37x+.20(20-x)=7.06
100(.37x+.20(20-x))=100(7.06)
37x+20(20-x)=706
37x+400-20x=706
17x+400=706
17x+400-400=706-400
17x=306
17x/17=306/17
x=18
Allen bought 18 37 cent stamps! (They didn't ask this time, but that means he only bought 2 20 cent stamps.)