A chemist wants to make a 10 solution of fertilizer How much

A chemist wants to make a 10% solution of fertilizer. How much water and how much of a 30% solution should the chemist mix to get 30 liters of a 10% solution?

Solution

30 litres of 10% solution = 30*0.1 = 3 L of pure fertilizer and 27 litre of water

let x be the amount of 30% solution

that implies

30 - x will be the amount of water, for which is 0% pure fertilizer

So

0.3 * x = 0 * (30-x) = 0.1 *30

0.3 x = 3

x= 10 liters of 30% solution

30 - x = 20 Litres pure water