[MikeyJ]

I have my orientation today and we are required to take a math test today (no calculators permitted). I can do everything with ease; however, I am confusing myself with a few ratio questions. Here are a few examples -- could someone tell me if I am doing them right?

Solve for X in each of the following. Be sure to label answers:

200mg:2ml::150mg:Xml

x=1.5 ml ?

50mg:1ml::35mg:Xml
x=0.7 ml ?

30mg:2ml::20mg:Xml
x=1.33 ml ?

Do those look right? I spoke with a 3rd semester nursing student and she told me they were not and showed me how to do them; however, her answeres were not making any sense. I am trying to think back to basic algebra, and I think I am setting them up right.

Any insight? Thanks!

[KIDNEYSareLIFE]

Totally right. Congratulations!!

[CseMgr1]

Originally Posted by sistermike

I have my orientation today and we are required to take a math test today (no calculators permitted). I can do everything with ease; however, I am confusing myself with a few ratio questions. Here are a few examples -- could someone tell me if I am doing them right?

Solve for X in each of the following. Be sure to label answers:

200mg:2ml::150mg:Xml

x=1.5 ml ?

50mg:1ml::35mg:Xml
x=0.7 ml ?

30mg:2ml::20mg:Xml
x=1.33 ml ?

Do those look right? I spoke with a 3rd semester nursing student and she told me they were not and showed me how to do them; however, her answeres were not making any sense. I am trying to think back to basic algebra, and I think I am setting them up right.

Any insight? Thanks!

You're right:

200 ml : 2 ml :: 150 ml : x ml.

200x = 300

x = 300/200 = 1.5

x= 1.5 ml.

[Daytonite]

Your answers are correct, but you really didn't show how you did the calculations to find the "X"s, so I don't know if your process of doing the math was correct. Doing them as ratios you would have cross multiplied. You can also set them up by dimensional analysis, factor out labels and common factors, and then multiply together everything that is left.

[mommapunkin]

I dont like the dots, maybe that is what was confusing you?? I like using the dimensional analysis method. The dots drive me crazy!!!! When the teacher would go about doing dots I put my fingers in my ears and go dododododododod lol To me the other way is soooo much easier! For some reason it just makes more sense that way. Good luck though.

[MikeyJ]

Thanks for everyones replies! I received a 100% on the math test today.

Sorry I didn't show how I did my work -- I just set them up as simple ratios and cross-multiplied. I found that to be easiest.

[nurse2btracy]

Originally Posted by CseMgr1

You're right:

200 ml : 2 ml :: 150 ml : x ml.

200x = 300

x = 300/200 = 1.5

x= 1.5 ml.

Math is not my strongest subject. I am a pre-nursing student waiting to hear from 2 schools. Can someone please help me understand this equation? How does 2ml become 200x? Does it have to do with the ml? Is this something I learn in dosages?

Thanks

[Megsd]

Originally Posted by nurse2btracy

Math is not my strongest subject. I am a pre-nursing student waiting to hear from 2 schools. Can someone please help me understand this equation? How does 2ml become 200x? Does it have to do with the ml? Is this something I learn in dosages?

Thanks

The way the equation is set up with the : is much like a fraction. 200 is on the top, 2 is on the bottom. 150 is on the top, x is on the bottom. To find the answer, you multiply the top numbers by the bottom numbers of the opposite fraction. So: 200 (top left) * x (bottom right) = 150 (top right) * 2 (bottom left)

This winds up being 200x = 300. Then divide both sides by 200 to get x = (300/200) which equals 1.5

Hope that makes more sense.

While you'll learn the specifics of dosages in school, most of this is algebra. You may want to refresh yourself on things like fractions and proportions before doing dosage calculations in school. Get a dosage calc book with refresher sections -- I had forgotten how to do fractions too until I got into school.

[brendamyheart]

Originally Posted by sistermike

Thanks for everyones replies! I received a 100% on the math test today.

Sorry I didn't show how I did my work -- I just set them up as simple ratios and cross-multiplied. I found that to be easiest.

Good job!!!!