Med Math: Drop Factors Question #6


500 mL of NS is to infuse over 5 hours. At what flow rate (mL/hr) is the IV running?


  1. 150 mL/hr
    • Rationale:
  2. 20 mL/hr
    • Rationale:
  3. 100 mL/hr
    • Rationale:
  4. 50 mL/hr
    • Rationale:



Normal Saline is to be infused. You would need to know how much volume in ml you need per hour in order to solve. The total volume is set at 500 ml to be infused. The hour is not converted to minutes to solve the problem. The 500 ml to be infused is divided by 5 hours. There is a simple formula below for calculating the flow rate. The final answer should have ml/hr within.


—– x 1 (understood to be 1 as in 1 hour)


500 mL/5 hrs = x/ 1hr = 100 mL/hr (no need to convert to min so keep the actual hrs to be infused)

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