Pipe A can fill a tank in 6 hours. Due to a leak at the bottom, it takes 8 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank?
Choose the correct choice from the following choices:	A) 13	B) 24	C) 18	D) 19	E) 12

Rationale: "let the leak can empty the full tank in x hours 1 / 6 - 1 / x = 1 / 8 = > 1 / x = 1 / 6 - 1 / 8 = ( 4 - 3 ) / 24 = 1 / 24 = > x = 24 . answer : b"
Answer: B