A pipe can empty 2/3rd of a cistern in 10mins. In 8 mins, what part of the cistern will be empty?
Answers:
A) 2 / 3
B) 3 / 7
C) 8 / 15
D) 3 / 8
E) 4 / 7

Rationale: "2 / 3 - - - - 10 ? - - - - - 8 = = > 8 / 15 c"
Answer: C