Problema Solution
you have 12 gallons of 20% alcohol racing fuel mixture. you want to add some amount of 100% alcohol in order to create a 50% alcohol fuel mixture. How many gallons of 100% alcohol do you have to add to your original 12 gallons of fuel?
Answer provided by our tutors
Let '1x' represent 'x' amount of 100% alcohol:
(12+x)0.5=1x+12*0.2
x=7.2
12+7.2=19.2
So 7.2 gallons of 100% alcohol should be added to 12 gallons of 20% alcohol in order to produce 19.2 gallons of 50% alcohol fuel mixture.