A 30% solution of fertilizer is to be mixed with a 60% solution of fertilizer in order to get 150 gallons of a 50% solution.How many gallons of the 30% solution and 60% solution should be mixed?

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30% is .3 as a decimal.  I do not know how many gallons of that I have, so I call that x.  Total for that solution is those multiplied so: .3x60% is .6 as decimal.  I do not know how many gallons of that I have but I do know that the total mixture is 150 gallons.  If I put x of those 150 gallons into the 30% solution then I have (150 - x) that goes into the 60% solution.  Total will be: .6(150 - x).Total for the mixture is 150 gallons at 50%, or .5 as a decimal.  That gives us: .5 * 150 = 75.When making the equation for a mixture problem, the first two totals add up to the mix total..3x + .6(150 - x) = 75Distribute the .6.3x + 90 - .6x = 75Combine like terms on left side-.3x + 90 = 75Subtract 90 from both sides-.3x = -15Divide both sides by -.3x = 50 gallonsThat is how many gallons of 30% solution to use.  To get how many gallons of 60% solution to use we subtract 50 from 100.150 - x = 150 - 50 = 100 gallons