## I am having trouble solving this alligation problem.

Rx: Normal saline. How many milliliters of water must you add to 500ml of a 10% stock solution of sodium chloride to make a batch of normal saline (sodium chloride 0.9% solution)?

Thanks for the good question. I have asked it on our Facebook Page Like this:

How many milliliters of water must you add to 100ml of a 10% stock solution of sodium chloride to make a batch of normal saline (sodium chloride 0.9% solution)?
A. 578
B. 790
C. 1011
D. none of the above

...
Hint: Formula to use (C1V1=C2V2)
(100)(.10)=(.009)(100+X)
Solve for X
----------
Try solving it with that formula and comment below with the answer.

## Comments for I am having trouble solving this alligation problem.

 Jan 24, 2012 Riduan by: Anonymous easy to do by: c1.v1=c2.v2 (.10).100=(.009).x 10=.009x 10/.009=x 1111=xnow 1111-100=1011 answer

 Sep 25, 2011 i got c by: Anonymous (100)(.10)=(.009)(100+x) multiply .009 to 100=.9 then multiply .009 by x 10 = .9 + .009x 10-.9=.009x 9.1=.009x --- --- .009 .009 x=1011

 Sep 12, 2011 ALLIGATION by: ebony I also came up with the same answer which is c. 100x10=10001000/0.009= 1111.11

 Aug 17, 2011 Answer is D by: Anonymous 91 mL of water needs to be added to the stock solution to make a normal saline of 0.9%10% - 0.9% = 9.1mL9.1mL x 10 = 91mL

 Jul 27, 2011 I still don't get it... by: BT from NC I still don't get it... ?

 Jul 15, 2011 CORRECT ANSWER IS C by: Anonymous 1000*10/100=10.9/100=.009NOW DIVIDE 10 BY.009 AND YOU GET 1111.111NOW SUBTRACT 100 FROM 111.111 AND YOU GET 1011.11SO THE ANSWER IS C

 Jul 10, 2011 alligation by: JK...NJ 500ml / .9 pats * 9.1 = 5,056 ml of water

 Jun 15, 2011 ANSWER by: Anonymous 5056 ML

 Jun 15, 2011 ANSWER by: lali 5006 ML

 May 29, 2011 I have the answer by: Anonymous I got 55.5

privacy