## Elementary Technical Mathematics

First determine the total number of drops to be administered. $500\ mL\times\frac{15\ drops}{mL}=7500\ drops$ Divide the number of drops by the flow rate to find the time. $7500\ drops\div\frac{25\ drops}{1\ min}=7500\ drops\times\frac{1\ min}{25\ drops}=300\ min$ $300\ min\times\frac{1\ hr}{60\ min}=5\ hr$