A solution contains 15 grams of drug in 300ml. What is its percentage strength?

To determine the percentage strength of a solution, you can use the formula:

[

\text{Percentage Strength} = \left( \frac{\text{amount of drug (g)}}{\text{total volume of solution (mL)}} \right) \times 100

]

In this case, you have 15 grams of a drug dissolved in 300 mL of solution. Plugging the values into the formula gives you:

[

\text{Percentage Strength} = \left( \frac{15 \text{ g}}{300 \text{ mL}} \right) \times 100

]

Calculating the fraction:

[

\frac{15}{300} = 0.05

]

Now, multiplying by 100 to convert it into a percentage:

[

0.05 \times 100 = 5%

]

This indicates that the percentage strength of the solution is 5%. It's important to carefully perform the calculations and ensure you understand how to apply the formula, as it will be relevant in various scenarios involving solution concentrations in pharmacy settings.

In this case, choosing 6% does not reflect the calculations involving the data given; thus, the correct percentage strength is