Pharmacy calculations worksheet with answers

Practice exercise (made-up values, not clinical guidance). A solution of potassium permanganate has a ratio strength of 1:5 000. How many milligrams m are in 250 mL?

A solution is 0.5% w/v. You need 21 mg of the drug. Draw up the volume in the syringe: what volume V is that?

Practice exercise (made-up values, not clinical guidance). A vial of penicillin G contains 5 000 000 units. Its practice label gives three strengths (see the table). You add 18.2 mL of diluent. The prescribed dose is 600 000 units. What volume V do you draw up? Round to one decimal place.

Practice exercise (made-up values, not clinical guidance). A vial contains ceftriaxone 1000 mg as a powder. The practice label says to add 9.6 mL of sterile water; the powder adds 0.4 mL to the volume. The prescribed dose is 600 mg. What volume V do you draw up? Round to one decimal place.

A vial holds 250 mg of powder. You add 3.8 mL of diluent, and the powder adds 0.2 mL of volume. The prescription is 50 mg. Draw up the dose: what volume V do you give?

Practice exercise (made-up values, not clinical guidance). You must prepare 750 mL of 13% sodium chloride by mixing 23% and 3% sodium chloride. How many mL V of the 3% solution do you need? Round to the nearest whole mL.