A pipe can empty 2/3rd of a cistern in 12mins. In 6 mins, what part of the cistern will be empty?  Pick one:
A) 2 / 3
B) 3 / 7
C) 4 / 9
D) 3 / 8
E) 1 / 3

Rationale: "2 / 3 - - - - 12 ? - - - - - 6 = = > 1 / 3 e"
Answer: E