Question 980535
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D=number of dimes; Q=number of quarters
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D=Q/4 Use this to substitute for D below.
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$0.10D+$0.25Q=$2.20 Substitute for D from above.
$0.10(Q/4)+$0.25Q=$2.20
$0.025Q+$0.25Q=$2.20
$0.275Q=$2.20
Q=8 She has 8 quarters.
D=Q/4=8/4=2 ANSWER: Mary has 2 dimes.
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CHECK:
$0.10D+$0.25Q=$2.20
$0.10(2)+$0.25(8)=$2.20
$0.20+$2.00=$2.20
$2.20=$2.20