SOLUTION: In a certain medical test designed to measure carbohydrate tolerance, an adult drinks 3 ounces of a 20% glucose solution. When the test is administered to a child, the glucose conc

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Question 770526: In a certain medical test designed to measure carbohydrate tolerance, an adult drinks 3 ounces of a 20% glucose solution. When the test is administered to a child, the glucose concentration must be decreased to 10%. How much 20% glucose solution and how much water should be used to prepare 3 ounces of 10% glucose solution?
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
{pure sugar}/{resulting solution}={concentration of resulting solution}

u = unknown ounces of 20% glucose
w = unknown ounces of water
20%2Au%2F%28u%2Bw%29=10 and u%2Bw=3


STEPS
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20u=10u+10w
10u=10w
u=w
-----------------
u+w=3
if u=w then substitute
u+u=3
2u=3
u=3/2
---------------------
highlight%28u=1%261%2F2%29 AND highlight%28w=1%261%2F2%29 ounces