5. Ceftriaxone 500 mg in 100 mL of 0.9 NS is to infuse over 40 minutes. The drop factor is 15 gtt/mL. What should the IV pump be programmed for? Round to whole number 6. The physician orders 0.9% NS 500 mL to be infused over 3 hours. The tubing drop factor is 20 gtt/mL. What is the flow rate setting as it infuses via gravity? Round to whole number