Question 655130
.90x+.25(250-x)=250*.80
.90x+62.5-.25x=200
.65x=200-62.5
.65x=137.5
x=137.5/.65
x=211.54 liters of 90% acid.
250-211.54=38.46 liters of 25% acid.
Proof:
.90*211.54+.25*38.46=250*.80
190.386+9.615=200
200=200