SOLUTION: A 3% saline solution is combined with a 5% saline solution to form 10 ounces of a 3.8% saline solution. How many ounces of the 3% solution are used?

Question 996276: A 3% saline solution is combined with a 5% saline solution to form 10 ounces of a 3.8% saline solution. How many ounces of the 3% solution are used?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = ounces of the 3% solution needed
Let = ounces of the 5% solution needed
-----------------------
(1)
(2)
------------------------------
(2)
(2)
--------------------
Multiply both sides of (1) by and
subtract (1) from (2)
(2)
(1)
--------------------

and
(1)
(1)
(1)
6 ounces of the 3% solution are needed
---------------
check:
(2)
(2)
(2)
(2)
(2)
OK
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