Question 458434
55x.5=27.5
w+z=55
.25w+.7z=27.5
25w+70z=2750
25w+25z=1375
45z=1375
z=30.55555
w=24.44444
You need 24.4444 gms. of 25% gold and 30.555555 gms. of 70% gold for your mix..