SOLUTION: Bob has saved quarters, dimes and pennies. He has 7 times as many quarters as dimes, and 6 times as many pennies as quarters. If he has a total of $29.51, how many pennies has he s

Algebra ->  Customizable Word Problem Solvers  -> Coins -> SOLUTION: Bob has saved quarters, dimes and pennies. He has 7 times as many quarters as dimes, and 6 times as many pennies as quarters. If he has a total of $29.51, how many pennies has he s      Log On

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Question 1085923: Bob has saved quarters, dimes and pennies. He has 7 times as many quarters as dimes, and 6 times as many pennies as quarters. If he has a total of $29.51, how many pennies has he saved?
Answer by math_helper(2461) About Me  (Show Source):
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q = number of quarters
d = number of dimes
p = number of pennies
q = 7d                  (1)
p = 6q = 6(7d) = 42d    (2)
25q + 10d + p =  2951   (3)  (in units of cents)

Using (1) and (2), we can express (3) in terms of 'd' only:
25(7d) + 10d + 42d = 2951
175d + 10d + 42d = 2951
227d = 2951
d = 2951/227 = 13 —> q=7*13 = 91 —> p= 6*91 = 546
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Ans: Bob has saved 546 pennies.
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Check: 546 + 10(13) + 91(25) = 546 + 130 + 2275 = 2951 (= $29.51 , so its good)