Problem: a tank contains 6,500 gallons of a solution that is 5 percent sodium chloride by volume . if 2,500 gallons of water evaporate from the tank , the remaining solution will be approximately what percent sodium chloride ?
Rationale: "we start with 6,500 gallons of a solution that is 5 % sodium chloride by volume . this means that there are 0.05 x 6,500 = 325 gallons of sodium chloride . when 2,500 gallons of water evaporate we are left with 4,000 gallons of solution . from here we can determine what percent of the 4,000 gallon solution is sodium chloride . ( sodium chloride / total solution ) x 100 = ? ( 325 / 4,000 ) x 100 = ? 0.0812 x 100 = ? = 8.12 % answer is d ."
annotated_formula: multiply(divide(multiply(multiply(const_100, const_100), divide(5, const_100)), subtract(multiply(const_100, const_100), add(multiply(add(const_2, const_3), multiply(multiply(add(const_2, const_3), const_2), const_100)), multiply(add(const_2, const_3), const_100)))), const_100)