Question 585245

A mixture of 6% disinfectant solution is to be made from 7% and 3% disinfectant solutions. How much of each solution should be used if 32 gallons of 6% solution are needed?
<pre>Let amount of 7% solution to mix, be S
Then amount of 3% solution to mix is, 32 - S
We then get: .07S + .03(32 - S) = .06(32)
.07S + .96 - .03S = 1.92
.07S - .03S = 1.92 - .96
.04S = .96
S, or amount of 7% solution to mix is: {{{highlight_green(matrix(1,4, .96/.04, "=", 24, gallons))}}}
Amount of 3% solution to mix is: {{{highlight_green(matrix(1,4, 32 - 24, "=", 8, gallons))}}}