Question

How many gallons of 20% salt solution must be mixed with 4 gallons of 40% salt solution to make 25% salt solution?

Answer 1

Answer:

4% gallons of 20% salt solution be needed

Answer 2

Answer:

since 25% is smack in the middle between 20% and 30% it will take a equal volum of each to make a 25% solution . Since 4 gallons of 30% solution was used, so 4 gallons of 20% solution will be needed.