SOLUTION: I need help. Word problems are the worst. $7.85 in quarters and dimes. If the number of dimes is 4 less than 3 times the quarters, how many dimes are in the bank?

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Question 953697: I need help. Word problems are the worst.
$7.85 in quarters and dimes. If the number of dimes is 4 less than 3 times the quarters, how many dimes are in the bank?
Found 3 solutions by stanbon, macston, lwsshak3:
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website!
$7.85 in quarters and dimes. If the number of dimes is 4 less than 3 times the quarters, how many dimes are in the bank?
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Value Equation: 10d + 25q = 785 cents
Quantity Eq::: d = 3q - 4
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Substitute for "d" and solve for "q"::
10(3q-4) + 25q = 785
30q - 40 + 25q = 785
55q = 825
q = 15 (# of quarters)
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solve for "d" using d = 3q-4
d = 3*15-4
d = 41 (# of dimes)
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Cheers,
Stan H.
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Answer by macston(5194)   (Show Source):
You can put this solution on YOUR website!
q=quarters; d=dimes=3q-4
$0.10d+$0.25q=$7.85 Substitute for d.
$0.10(3q-4)+$0.25q=$7.85
$0.30q-$0.40+$0.25q=$7.85 Add $0.40 to each side.
$0.55q=$8.25
q=15 ANSWER 1: There are 15 quarters in the bank.
d=3q-4=3(15)-4=41 ANSWER 2: There are 41 dimes.
CHECK
$0.10d+$0.25q=$7.85
$0.10(41)+$0.25(15)=$7.85
$4.10+$3.75=$7.85
$7.85=$7.85

Answer by lwsshak3(11628)   (Show Source):
You can put this solution on YOUR website!
I need help. Word problems are the worst.
$7.85 in quarters and dimes. If the number of dimes is 4 less than 3 times the quarters, how many dimes are in the bank?
***
let x=number of quarters
3x-4=number of dimes (number of dimes is 4 less than 3 times the quarters)
..
each quarter is worth .25
each dime is worth .10
.25x+.10(3x-4)=7.85
.25x+.30x-.40=7.85
.55x=8.25
x=15
3x-4=45-4=41
how many dimes are in the bank? 41
Check:
41 dimes=4.10
15 quarters=3.75
4.10+3.75=7.85