Question 201644: sarah has 27 coins,all quarters and nickles which add up to $6.55. how many quarters does she have ?
Answer by Earlsdon(6294)   (Show Source):
You can put this solution on YOUR website! Let N = the number of nickels and Q = the number of quarters.
1) N+Q = 27 "Sarah has 27 coins, all quarters (Q) and nickels (N)..."
2) $0.05N+$0.25Q = $6.55 "...which add up to $6.55
Rewrite equation 1) as N = 27-Q and substitute this into equation 2), then solve for N.
$(0.05)(27-Q)+$0.25Q = $6.55 Simplify the left side.
$1.35-0.05Q+0.25Q = $6.66 Add/subtract the Q-terms on the left.
$1.35+0.2Q = $6.55 Subtract $1.35 from both sides.
0.2Q = $5.20 Divide both sides by 0.2
Q = 26 and N = 27-Q
N = 27-26 = 1
Sarah has 1 nickel and 26 quarters.
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