You can
put this solution on YOUR website!Let x= 20% alloy; y= 27% alloy
Set up system of equations:
.20x+.27y=24.9
x+y=100 -->multiply by -.20
.20x+.27y=24.9
-.20x+-.20y=-20.00
.07y=4.9
y=70 -->plug back into one of the original equations
x+70=100
x=30
30 ounces of 20% alloy; 70 ounces of 27% alloy