Question 490075
a pharmasist wishes to mix a solution that is 7% minoxidil. 
she has on hand 80 ml of a 4% solution and wishes to add some 9% solution to obtain the desired 7% solution. 
how much 9% solution should she add?
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Equation:
mino + mino = mino
0.04*80 + 0.09x = 0.07(80+x)
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Multiply thru by 100 to get:
4*80 + 9x = 7*80 + 7x
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2x = 3*80
x = 120 ml (amt of 9% solution needed)
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Cheers,
Stan H.
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