SOLUTION: You go to the post office to buy stamps. You want 9 cent stamps. you want 4 times as many 13 cent stamps as 9 cent stamps and some 3 cent stamps. You give the clerk $5.00 and wan

Algebra ->  Divisibility and Prime Numbers -> SOLUTION: You go to the post office to buy stamps. You want 9 cent stamps. you want 4 times as many 13 cent stamps as 9 cent stamps and some 3 cent stamps. You give the clerk $5.00 and wan      Log On


   



Question 179425: You go to the post office to buy stamps. You want 9 cent stamps. you want 4 times as many 13 cent stamps as 9 cent stamps and some 3 cent stamps. You give the clerk $5.00 and want no change. What stamps do you get?
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
You go to the post office to buy stamps. You want 9 cent stamps. you want 4 times as many 13 cent stamps as 9 cent stamps and some 3 cent stamps. You give the clerk $5.00 and want no change. What stamps do you get?
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Let x = # of nine cent stamps ; their value is 9x cents
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4x = # of 13 cent stamps ; their value is 13*4x = 52x cents
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# of 3 cent stams = "t" ; their value is 3t cents
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Equation:
value + value + value = 500 cents
9x + 52x + 3t = 500
61x + 3t = 500
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Let x = 8 ; 61x = 488
Let t = 4 ; 3t = 12
and 61*8 + 3*4 = 500
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If x = 8, 9x = 72 cents (eight 9-cent stamps)
and 52x = 52*8 = 416 cents (thirty-two 13-cent stamps)
and 3t = 12 cents (four 3-cent stamps)
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Cheers,
Stan H.