Question 1077037
x=10%

.10(x)+.50(50)=.20(50+x)
.10x+25=10+.20x
-.10x=-15
x=150 gallons of 10% salt.
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To go from 50% to 20% is 3/4 of the way to 10%
150 gallons of the final 200 gallon mixture is 3/4 of the mixture.