Question 1085259
 The radiator truck contains 12 gallons of water.
 We draw off 3 gallons and replace it with alcohol,
Find the percent alcohol in decimal form, when this is done
{{{3/12}}} = .25
 then draw off 3 gallons of the mixture and replace it by alcohol, etc., how much alcohol is in the final mixture?
let x = the percent of alcohol in the final mixture 
.25(12-3) + 3 = 12x
.25(9) + 3 = 12x
2.25 + 3 = 12x
5.25 = 12x
x = 5.25/12
x = .4375 * 100 = 43.75% alcohol in the final mixture