Question 71604
If the 1000 gallon tank of water contains 6% salt, then it's total salt content is 1000 X .06, or 60 gallons.  To find out how much water we need to thin that we use Gls. X .04 equals 60.  Thus 60/.04 = 1500 is our total gallons.  Since we started with 1000 gallons, we need 500 more gallons of pure water to reach our 4% solution.