Question 1031141
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I'm having problems doing this word problem. Somebody help! Here it is:
A pharmacist mixed some 10% saline solution 
with some 15% saline solution to obtain 100ml of a 12% saline solution. How much of the 10% saline solution did the pharmacist use in the mixture?

Now, here is my work that i did. I made a 3 variable equation and something seems to not work there. Could you please show me what i did wrong or come up with a new way to approach the problem?
x+y=z
10x+15y= 100(12z)
Thanks a ton! 
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Your equations are (or should be)

  x +   y = 100,      (1)
10x + 15y = 12*100.   (2)


NO THREE EQUATIONS !   NO THREE UNKNOWNS !   Only two. 


Could you complete the solution from this point?


There are many similar solved problems in this site that you can use as samples.
See the lesson  <A HREF=https://www.algebra.com/algebra/homework/word/mixtures/Solving-typical-mixture-problems.lesson>Solving typical word problems on mixtures for solutions</A>  in this site.
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