15 gtts/ml Order: Infuse 1000 ml NS over 4 hours.  The nurse…

15 gtts/ml Order: Infuse 1000 ml NS over 4 hours.  The nurse retrieves the IV set below from the supply closet and  establishes the infusion as ordered.  What is the rate for the infusion (gravity infusion, NO pump) using the IV set noted below?    (gtt/min)