Question

A salt solution of 15 litres contains 20%salt. How much water must you add to salt solution, in order to dilute it 15% salt?

Answer 1

3 litres

Answer 2

you are diluting it 20/15=1.333 time, which means one part of the original (1 part = 15 liters) and .333 parts water (.333*15)=5 liters water.