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 le

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Question 224313: (((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 that the number of 8 cent stamps. The total value of all the stamps is $2.47. Find the number of 8 cent stamps in the collection.)))
I have tried every way I can think of to make an equation to solve this problem. I have been unable to do so. If I could get some help to come up with an equation for this problem I would be most grateful.
Answer by stanbon(75887) About Me  (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.
Eq:; e = 3t-1
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The number of 15 cent stamps is six less that the number of 8 cent stamps.
Eq: f = e-6
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The total value of all the stamps is $2.47.
Eq: 3t + 8e + 15f = 247 cents
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Find the number of 8 cent stamps in the collection.
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Rearrange the three equations and solve for "e":
3t - e + 0 = 1
0t + e - f = 6
3t + 8e+15f = 247
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Subtract the 1st from the 3rd
3t - e + 0 = 1
0t + e - f = 6
0t + 9e+15f = 246
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Add 15 times the 2nd to the 3rd
3t - e + 0 = 1
0t + e - f = 6
0t +24e+ 0f = 336
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Solve the 3rd for "e":
24e = 336
e = 14 (# of 8 cent stamps)
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Cheers,
Stan H.