How much water must be evaporated from 64 ounces of a 2% salt solution to make a 10% salt solution?

64 ounces of a 2% salt solution contains 1.28 ounces of salt and thus 62.72 ounces of water.

The mass of the 10% solution is (x+1.28), where x is the mass of water.
1.28 divided by (x+1.28) must be equal to 10%.


The 10% solution contains 11.52 ounces of water.


51.2 ounces of water must be evaporated.