Question 234380
Q+D=20 OR Q=20-D
.25Q+.10D=3.80
.25(20-D)+.10D=3.80
5-.25D+.10D=3.80
-15D=3.80-5
.15D=1.20
D=1.20/.15
D=8 NUMBER OF DIMES.
Q=20-8=12 NUMBER OF QUARTERS.
PROOF:
.25*12+8*.10=3.80
3+.80=3.80
3.80=3.80