A patient requires 250 mg of a drug, which is available in a 200 mg/5 mL solution. How many mL do you need to administer?

To determine the correct volume of the solution needed to administer the required dosage of the drug, you can use a simple dimensional analysis or ratio proportion method. The concentration of the solution is given as 200 mg in 5 mL, which means for every 5 mL, there are 200 mg of the drug available.

First, calculate how many mg are in 1 mL of the solution:

200 mg / 5 mL = 40 mg/mL.

Next, to find out how many mL you'd need to administer 250 mg, you can set up a proportion:

If 40 mg corresponds to 1 mL, then 250 mg corresponds to X mL.

Using the formula:

X mL = (250 mg) / (40 mg/mL).

Calculating this gives:

X = 250 / 40,

X = 6.25 mL.

Therefore, to administer 250 mg of the drug, you need to provide 6.25 mL of the 200 mg/5 mL solution. This is why the correct answer is the option that states 6.25 mL.