# A nurseryman is preparing an insecticide by mixing a 95% solution with water (0% solution). How much solution and how much water are needed to fill a 100 L tank with 3.8% solution?

##### 1 Answer

You need **4 L** of solution and **96 L** of water.

#### Explanation:

The key to solving this problem is understanding that **all** the solute that exists in the **100-L** solution comes from the 95% solution.

This means that you can figure out how much solution you need to mix with water by calculating how much solute you get in the final 100-L sample.

This means that you have

Now use the percent concentration of the 95% solution to figure out how much solution would contain **3.8 L** of solute

This means that you need

The volume of water would be