Dr ordered 15% strength solution to be prepared. How many grams of pure drug are needed to make 25 ml to make solution?

1. A 15% strength solution means that 15% of the entire solution is pure drug.
2. To find out how many grams of pure drug are needed for 25 ml of solution, we'll use the formula:

\text{Amount of pure drug} = \text{Percentage strength} \times \text{Volume of solution}

3. Substitute the given values into the formula:

\text{Amount of pure drug} = 0.15 \times 25

4. Calculate the amount of pure drug:

\text{Amount of pure drug} = 3.75 \text{ grams}

5. Therefore, the number of grams of pure drug needed to make 25 ml of a 15% solution is

3.75 \text{ grams}