A patient is prescribed IV infusion at 6 ml/hr for 15 hours. The drug solution contains 120 mg/60 ml. How much drug (in mg) will the patient receive?

Correct option is B

Total infused volume = 6 × 15 = 90 ml. Drug strength = 120 ÷ 60 = 2 mg/ml. Therefore, 90 × 2 = 180 mg of drug is delivered over 15 hours.
Explanation of options: (a) ✘ 160 mg comes from assuming only 80 ml infused instead of 90 ml. This underestimates the dose. (b) ✔ Correct; calculation shows exactly 180 mg with the given rate and concentration. It matches both time and drug strength. (c) ✘ 200 mg assumes 100 ml infused, which would occur at ~16.7 hours, not 15. So it is incorrect. (d) ✘ 240 mg corresponds to 120 ml infusion (20 hrs), not the 15 hrs in this case.