If 40% of 15 L of a weed killer is water, how much water can be added to make it contain 75% water?

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Answer 1

There is 40% of 15L = 6L of water in the solution.

So amount of weed killer in the solution = 60% of 15L = 9L

Let the amout of new solution in litres be x.

Since the amount of weed killer in the solution remains constant.

So in the new solution after water being added, the amount of weed killer remains 9L or 25% of x.

So, x * 25% = 9

=> x = 9*100/25 = 36L

Therefore the amount of water added to the solution = 36-15 = 21L

Answer 2

If 40% of 15 L of a weed killer is water, how much water can be added to make it contain 75% water?