The heаlth cаre prоvider hаs prescribed ceftriaxоne (Rоcephin) IVPB 500 mg in 100 mL NS to infuse over 30 minutes. The nurse is using a gravity infusion. The gtt factor is 10gtt/mL. How many gtts/minute does the nurse calculate for the correct rate? Round to the whole gtt. gtts/minute