A medication has a concentration of 50 mg/mL. How many milliliters are needed to obtain a dose of 200 mg?

To determine how many milliliters of a medication with a concentration of 50 mg/mL are needed to obtain a dose of 200 mg, you can use the formula:

[

\text{Volume} = \frac{\text{Dose}}{\text{Concentration}}

]

Substituting the given values into the formula:

[

\text{Volume} = \frac{200 \text{ mg}}{50 \text{ mg/mL}} = 4 \text{ mL}

]

Thus, to achieve a dose of 200 mg, you would need 4 mL of the medication, as it provides the exact required amount of drug. This calculation directly shows how the concentration relates to the volume needed for the desired dose.

The choice indicating 5 mL would provide a dose of 250 mg (5 mL x 50 mg/mL), which exceeds the required 200 mg. Similarly, selecting lower volumes of 3 mL or 2 mL would result in doses of only 150 mg and 100 mg, respectively, both of which would be insufficient. Therefore, the correct amount required is indeed 4 mL.