A storage tank contains 150 liters of a liquid solution comprising fruit syrup and water, of which 80% is fruit syrup. If 20% of the solution is drawn off and 30 liters of pure water is added to the tank, what is the percentage of water in the resulting mixture?

The correct answer is 36.

Step 1: Determine the initial volume of fruit syrup and water in the mixture.
The total initial volume of the solution is 150 liters.
Since 80% of the solution is fruit syrup, the remaining 20% is water.

$\text{Initial syrup volume}=80\%\times 150=\frac{80}{100}\times 150=120\text{liters}$

$\text{Initial water volume}=20\%\times 150=\frac{20}{100}\times 150=30\text{liters}$

Step 2: Calculate the remaining volumes of syrup and water after 20% of the solution is drawn off.
Drawing off 20% of the total solution reduces the volume of both components by 20%.

$\text{Volume of solution removed}=20\%\times 150=30\text{liters}$

$\text{Remaining total volume}=150-30=120\text{liters}$

$\text{Remaining syrup volume}=80\%\times 120=\frac{80}{100}\times 120=96\text{liters}$

$\text{Remaining water volume}=20\%\times 120=\frac{20}{100}\times 120=24\text{liters}$

Step 3: Calculate the volumes after adding 30 liters of pure water.
When 30 liters of pure water is added, the volume of fruit syrup remains unchanged at 96 liters, while the volume of water increases by 30 liters.

$\text{New water volume}=24+30=54\text{liters}$

$\text{New total volume}=120+30=150\text{liters}$

Step 4: Find the percentage of water in the final mixture.
The percentage of water in the new solution is calculated as the ratio of the new water volume to the new total volume, multiplied by 100%.

$\text{Percentage of water}=\frac{\text{New water volume}}{\text{New total volume}}\times 100\%$

$\text{Percentage of water}=\frac{54}{150}\times 100\%=36\%$

Therefore, the percentage of water in the resulting mixture is 36%.