A chemist mixes one liter of pure water with x liters of a 30% salt solution, and the resulting mixture is a 20% salt solution. What is the value of x?
Choose the correct choice from the following options
A) 1 / 4 B) 1 / 3 C) 1 / 2 D) 1 E) 2

Rationale: "concentration of salt in pure solution = 0 concentration of salt in salt solution = 30 % concentration of salt in the mixed solution = 20 % the pure solution and the salt solution is mixed in the ratio of - - > ( 30 - 20 ) / ( 20 - 0 ) = 1 / 2 1 / x = 1 / 2 x = 2 answer : e"
Answer: E