A tank contains 7,500 gallons of a solution that is 6 percent sodium chloride by volume. If 2,000 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?
Choose the correct answer
A) 5.18%
B) 6.18%
C) 7.18%
D) 8.18%
E) .7%
We start with 7,500 gallons of a solution that is 6% sodium chloride by volume. This means that there are 0.06 x 7,500 = 450 gallons of sodium chloride.   When 2,000 gallons of water evaporate we are left with 5,500 gallons of solution. From here we can determine what percent of the 5,500 gallon solution is sodium chloride.   (sodium chloride/total solution) x 100 = ?   (450/5,500) x 100 = ?   0.081 x 100 = ?   = 8.18%   Answer is 8.18%.
<result>D</result>
A tank contains 7,500 gallons of a solution that is 6 percent sodium chloride by volume. If 2,000 gallons of water evaporate from the tank, the remaining solution will be approximately what percent sodium chloride?