Question 123813
n+d=10 or n=10-d
.05n+.10d=.85
.05(10-d)+.10d=.85
.5-.05d+.10d=.85
.05d=.35
d=.35/.05
d=7 number of dimes.
10-7=3 number of nickels.
proof
.05*3+.10*7=.85
.15+.70=.85
.85=.85