Question 318407
A chemist has two salt solutions. One solution is 20 percent salt and the other solution is 45 percent salt. How many liters of each must be used to produce 100 liters of a solution that is 37.5 percent salt?
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One solution is 20 percent salt  x liters
the other solution is 45 percent salt. 100-x
Total 100 liters  37.5 percent salt?
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Concentration equation
0.2x+0.45(100-x)=100*0.375
0.2x+45-0.45x=37.50
-0.25x=37.50-45
-0.25x=-2.5
x=-2.5/0.25
x= 10 liters of 20% solution
balance will be 45% solution = 90 liters