SOLUTION: A stamp collection consists of 3, 8 and 15 cent stamps. The number of 8 cent stamps is one less than triple the number of 3 cent stamps. The number of 15 cent stamps is six less
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Question 174473: A stamp collection consists of 3, 8 and 15 cent stamps. The number of 8 cent stamps is one less than triple the number of 3 cent stamps. The number of 15 cent stamps is six less than the number of 8 cent stamps. The total value of all the stamps is $2.47. Find the number of 8 cent stamps.
I can not figure out the formula to work this problem. Can you please explain.
Thanks Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website! A stamp collection consists of 3, 8 and 15 cent stamps.
The number of 8 cent stamps is one less than triple the number of 3 cent stamps.
e = 3t-1
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The number of 15 cent stamps is six less than the number of 8 cent stamps.
f = e - 6
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The total value of all the stamps is $2.47
3t+8e+15f = 247
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Find the number of 8 cent stamps.
EQUATIONS:
t = (e+1)/3
f = e - 6
8e = 247-3t-15f
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Substitute for t and for f to solve for e:
8e = 247 -3(e+1)/3 - 15(e-6)
8e = 247 -e - 1 -15e + 90
8e = 336 - 16e
24e = 336
e = 14 (number of eight cent stamps)
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Cheers,
Stan H.
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