# PTCB practice test 19 question 7

#7

A patient is receiving an infusion from a 500mL bag containing a 0.5% solution of drug S. The drop factor is calibrated at 12gtt/mL and the flow rate is set to 10gtt/min. If the infusion is to run for 4 hours, how much of the active drug will the patient receive.

A. 1200mg
B. 1000mg
C. 500mg
D. 200mg

How is this done? It says the answer is C but I cannot seem to get that.

### Comments for PTCB practice test 19 question 7

 Reworked the problem by: Anonymous I just reworked the problem and got an answer of 200 mg. which is "d". I converted the 4 hours to 240 min., took that by the 10 gtt/min to get 2400 drops. I then divided that answer by the 12 gtt/ml to get 200 ml received. If that is correct so far, I set up my proportion of 500 mg (0.5%)/500 ml = x/200 ml. x=200 mg.

 sneaky! ;) by: Anonymous The answer is 500mg, but it's kind of a trick question. The information suggests that you work it as a flow rate problem, but in reality you're already told that you're dispensing 500mL over 4 hours with the constant and the rate, so the only thing you're really looking at here is the 0.5% solution, which is....0.5% = 0.5g = 500mgHope that helps! :)

 REALLY..... by: Anonymous Oh my goodness I was so mad at this problem I was stomped for over 30 minutes but thanks so much really helps and yes it was a sneaky set up :)

 The answer is B by: Anonymous The answer is B, 1000mgIt's a flow rate question.4 hrs * (60 min/hr) * (10gtt/min) * (1 mL/12gtt) * 0.5% (w/v) = 200 mL * 0.5% = 1 g = 1000 mg

 confused by: Anonymous theres 3 different answers can someone else shed some lights on this question?

 light already shed by: Anonymous It was already stated that the given answer was C. 500 mg

 easy by: Anonymous %0.5=5mg in 1ml or 12gtt10gtt or 4.16mg per min. = 1000mg per 4 hours