A nurse is preparing to infuse a 250-mL unit of packed RBCs over 2 hr. The drop factor of the manual IV tubing is 15 gtts/mL. The nurse should adjust the flow rate to deliver how many drops per minute? (Round the answer to the nearest whole number. Do not use a trailing zero.)

Rationale: Total volume = 250 mL Time = 2 hr = 120 minutes Drop factor = 15 gtts/mL Use the formula: Flow rate (gtts/min) = (Volume in mL × Drop factor) ÷ Time in minutes = (250 × 15) ÷ 120 = 3750 ÷ 120 = 31.25 → Round to the nearest whole number = 31 gtts/min