Med Math: Drop Factors Question #12


Orders are to infuse 1000 mL NS to run at 100 mL/hr. How long will the IV infusion run?


  1. 5 hr
    • Rationale:
  2. 12 hr
    • Rationale:
  3. 10 hr
    • Rationale:
  4. 8 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 1000 ml to be infused. The hour is not converted to minutes or needed to solve the problem. The 100 ml/hr will be used during the solving of the calculation to determine the infusion time. There is a simple formula below for calculating the infusion time. The final answer should have hr within.

Total Volume in ML

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


1000 ml

———- = 10 hr

100 ml/hr

1000 mL/100 mL = 10 hr

Learning Outcomes

Test Taking Tip

Video Rationale