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Question 70863: Please help me!!!!: Solution X is 20% alchohol, and solution Y is 80% alchohol. How much of each should be used to make 300 / of a 50% solution.
Answer by ankor@dixie-net.com(22740)   (Show Source):
You can put this solution on YOUR website! Solution X is 20% alchohol, and solution Y is 80% alchohol. How much of each should be used to make 300 / of a 50% solution.
:
Just by looking at the problem it seems it would be half 20% and half 80%
since both are 30% away from 50%. However, here is the algebra way
;
We know the two solutions will total 300 units
x + y = 300
or
y = 300 - x
:
Write the per cent equation:
.20x + .80y = .50(300)
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Substitute (300-x) for y in the above equation (from the 1st equation)
.20x + .80(300-x) = .50(300)
:
Multiply what's inside the brackets and you have;
.20x + 240 - .80x = 150
:
.20x - .80x = 150 - 240
-.60x = - 90
x = -90/-.6
x = + 150 units of 20% stuff, of course 150 units of the 80% also
:
Is this what you had in mind?
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