Please Help With a Math Problem

I can't seem to understand how to figure out these types of problems. Please help...

"The doctor orders a 3/4 - strength formula tube feeding for the pt. The formula comes in cans containing 240mL. How much water will the nurse add to the can of formula to make the ordered 3/4 strength diluted tube feeding?"

thanks in advance.

8 Answers

3/4 strength means that it will be 3 parts formula and one part water. Take the 240mL and divide it by three to give you 80mL. Add 80mL of H2O to the 240mL of formula to make 3/4 strength.

You can actually do it two ways. You can add 80ml of water. This would give you a total of 320ml of which 80ml(25%) is water. So you would be at the MD order of 3/4 strength. OR you could save or discard 60ml of tube feed solution and replace with 60ml of water. But option two here may be wasteful.

Specializes in home health, dialysis, others.

80 ml is the correct answer. 3 parts formula and one part water.

3/4 strength means that it will be 3 parts formula and one part water. Take the 240mL and divide it by three to give you 80mL. Add 80mL of H2O to the 240mL of formula to make 3/4 strength.

Another way to explain it is that the 240ml is going to be 3/4 of the total solution. So, you take the Equation 240 = .75x

From here you use simple algebra to divide 240/.75 = x = 320 which is the total volume of the final product. The difference in the beginning product 240 and the final product 320 is 80ml.

Hope that helps explain it.

Chuck

:yeah: I would just take the total 240ml and divide by 0.75. That will give you your total volume of 80 ml of water!! Hope this helps. :clown:

Hugs and God Bless

I think you would take 240 and divide that by 4 which would be 60 so you would add 60ml of water to make it 3/4 strength. Maybe not though...

I thought that was the way to do it also. The workbook I am using shows the answer as 80mL. The textbook is not required so I can't even look how to work out the problem. Thanks

Thank you to all. This really helps.

GREATLY APPRECIATED :)

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