A patient receives an IV of 20,000 units of heparin in a 100mL bag over 45 minutes. If the set is calibrated to drop 15gtt/mL, what is the drops per minute rate?

In the first sentence they tell you 100 mL is given over 45 minutes >>>>> 100 mL/45 minutes You want gtt/min and they give you gtt/mL. Multiply 15 gtt/mL by 100 mL to get 1500 gtt. Divide this by 45 minutes to get ~33.3 gtt/min.