Question 213388
how many gallons of pure alcohol should be mixed with 20 gallons of a 15% alcohol solution to obtain a mixture that is 25% alcohol?
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alcohol + alcohol = alcohol
0.15*20 + x = 0.25(20+x)
Multiply thru by 100 to get:
15*20 + 100x = 25*20 + 25x
75x = 10*20
x = 2 2/3 gallons (amount of 100% alcohol needed for the mixture)
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Cheers,
Stan H.