Answer:
q + n = 55
.25q + .05n = 10.15
.25(55 - n) + .05n = 10.15
13.75 - .25n + .05n = 10.15
13.75 - .20n = 10.15
.20n = 3.60
n = 18 nickels
q = 55 - 18 = 37 quarters
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