Question 1115355: Joe has a collection of 25 coins, dimes and nickels worth total of $1.80. Find number of dimes and number of nickels he has. Answer by addingup(3677) (Show Source):
You can put this solution on YOUR website! d+n = 25 subtract dimes:
n = 25-d
0.10d+0.05n = 1.80
substitute for n:
0.10d+0.05(25-d) = 1.80
0.10d+1.25-0.05d = 1.80
0.05d = 0.55
d = 0.55/0.05 = 11
Joe has 11 dimes
Joe has 25-11 = 14 nickels
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check:
11 dimes = 11(0.10) = 1.10
14 nickels = 14(0.05) = 0.70
and 1.10 + 0.70 = 1.80 Correct
