Problema Solution

A 10% salt solution is to be mixed with a 20% salt solution to produce 20 gallons of a 17.5% salt solution. How many gallons of the 10% solution and how many gallons of the 20% solution will be needed?

Answer provided by our tutors

let x gallon of 10% solution and y gallon of 20% solution

x+y= 20

and

0.1x+0.2y=0.175 *20

=> 0.1(20-y)+0.2y= 3.5

=> 2-0.1y+0.2y=3.5

=> 0.1y= 1.5

=> y=15

x=20-15=5