Question

How many gallons of a 15% sugar solution must be mixed with 5 gallons of a 40% sugar solution to make a 30% sugar solution?

Answer 1

Let number of gallons of a 15% sugar solution must be mixed be X

Then 15/100*X+40/100*5=30/100*(X+5)

divide both sides by 100

15X+200=30X+150

30X-15X=200-150

15X=50

X=50/15=3.33

Number of gallons of a 15% sugar solution must be mixed with 5 gallons of a 40% sugar solution to make a 30% sugar solution=3.33 gallons