Can someone check my math?

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Here's the problem. No matter how I do it I come up with 83 minutes, but the answer keeps getting marked wrong. I am not usually weak at math, but I do not want to assume the questions is wrong.

A nurse is administering 350 ml of fluid. The infusin rate is 42 gtt/min and the drop factor is 10gtt/ml. Calculate the number of minutes to infuse the fluid.

I suck at dimensional analysis, but will tell how I did my math.

42gtt/min = 4.2 ml/min

350ml/4.2ml = 83 min

Am I missing something?

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Specializes in Neonatal Nurse Practitioner.

I get 83.3 minutes.

Using dimensional analysis:

1min/42gtts x 10gtts/1mL x 350mL

Did it tell you to round?

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I get 83.3 which rounds to 83 minutes.

Using dimensional analysis:

1min/42gtts x 10gtts/1mL x 350mL

Did it tell you to round? I would have gone with 83.3 minutes.

Yes, it said to round. Sorry didn't include that.

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Just to confirm using dimensional analysis I got 83.3

350mL x 1 min/42gtt x 10gtt/1mL

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Specializes in Neuro, Telemetry.

Round doesnt always mean to the whole minute. It just means to use the rounding rules you are given by your instructor. In my program we are simply told to round all answers. For this question we would round to the 10th. And then from there we would be required to list the time as hours and minutes. If there are seconds left over, it would just depend on instructions. Some want second and some don't. Try using 83.3 and if that doesnt work then enter hours then minutes and see what it says.

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Round doesnt always mean to the whole minute. It just means to use the rounding rules you are given by your instructor. In my program we are simply told to round all answers. For this question we would round to the 10th. And then from there we would be required to list the time as hours and minutes. If there are seconds left over, it would just depend on instructions. Some want second and some don't. Try using 83.3 and if that doesnt work then enter hours then minutes and see what it says.

It said round to the nearest whole number. I looked and they have a mistake on the rationale. I didn't catch it because the rationale was in dimensional analysis. It's totally missing a step. Thanks for your help.

By the way, I'm quite proud of myself I actually solved a bunch of problems on my own using dimensional analysis. I made myself use that method and then check it with how I usually do math (ratio and proportions). I am getting tired of not understanding rationales because I don't use that method. Actually, I might even say it aloud it *is* kind of easier now that I am starting to get it.

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Once you get use to using dimensional analysis, it makes things easier and helps to keep you organized in setting up a problem in my opinion. If you haven't already check out Khan acadamey to see if they have any thing about dimenisional analysis on there. I have been using the site for reviewing math skills that I haven't used in 8 years to prepare for taking an assesment test at school so that I can work on getting the math class that I will need for when I eventually work on completing my BSN taken care of by the end of this summer. The videos on the site and the way that I have found that Sid explains the concepts to be easily understood. I am sure there are other videos that you could find on youtube also that would go over setting up a dimensional analysis problem :up:

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