SOLUTION: You need a 30% alcohol solution. On hand, you have a 385 mL of a 10% alcohol mixture. You also have 85% alcohol mixture. How much of the 85% mixture will you need to add to obtain

Question 906620: You need a 30% alcohol solution. On hand, you have a 385 mL of a 10% alcohol mixture. You also have 85% alcohol mixture. How much of the 85% mixture will you need to add to obtain the desired solution?
Answer by richwmiller(17219) (Show Source): You can put this solution on YOUR website!
0.85*x+0.1*385=0.3(385+x)
0.85*x+38.5=115.5+0.3x
0.85x-0.3x=115.5-38.5
0.55x=77
x=140 mL at 85% is added to 385 mL at 10% to get 525 mL at 30%
check
0.85*140+0.1*385=0.3(385+140)
119+38.5=0.3(525)
157.5=157.5
ok

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