A research chemist has two different salt water solutions. Solution 1 is 25% salt and solution 2 is 20% salt. She wants to have 1 liter of 22% solution. How much of each solution should she mix together to get the desired solution?

Answer 1

amount of solution #1 --- x L
amount of solution #2 ---- 1-x L

.25x+ .20(1-x) = .22(1)

solve for x

btw, this would not be considered Calculus.