Solving A Mathematics Problems

Question

What solution consisting of 323mg of dopamine in 34ml of solution is administered at rate of 10ml/Hr and what is the flow rate in mg of dopamine per hour?

Answer 1

323 mg in 34 ml.

So in 1 ml there will be (323 / 34) mg

So in 10 ml there will be (323/34) x 10 mg = 95 mg

As 10 ml is infused per hour, 95 mg / hr is the infusion rate of the dopamine.

Maybe this is an easier way of looking at it then William's solution, because it focuses more on the logic than fraction manipulation.

Mike

Answer 2

Notice that if you set it up correctly, the units you don't want in your answer will cancel out and the units that you do want in your answer will be left.

Your answer calls for mg/hr so since there are mg on top (in the numerator), we need to start out with a number that has mg on top, like 323 mg/34mL. Since you DON'T want mL in your final answer, and since mL is on the bottom (in the denominator), you need to multiply by something with mL on top, like 10 mL/1 hr. After you cancel the mL, the units left are what you want, mg/mL. So now, you just need to multiply the numbers on the top and divide by the numbers on the bottom. So, 323 times 10 divided by 34 = 95 mg/hr