How many gallons each of 30% alcohol and 5% alcohol should be mixed to obtain 25 gal of 17% alcohol?

Question

How many gallons each of 30% alcohol and 5% alcohol should be mixed to obtain 25 gal of 17% alcohol?

Answer 1

Let x = the number of gallons of 30% solution and 25-x = the amount of 5% solution.

Then

{ 30x+ (25-x)5 }/25 = 17 or 30x + 125 - 5x = 425 or 25x= 300

So, x = 12 gallons (30%) and 25-x = 13 gallons (5%)