## 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)?

**Reply (by Keith)**

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

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Try solving it with that formula and comment below with the answer.