Pipe A can fill a tank in 8 hours. Due to a leak at the bottom, it takes 12 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.
A) 5  B) 24  C) 78  D) 90  E) 54
Let the leak can empty the full tank in x hours 1/8 - 1/x = 1/12   =&gt; 1/x = 1/8 - 1/12 = (3 - 2)/24 = 1/24   =&gt; x = 24.   Answer: 24
<result>B</result>
Pipe A can fill a tank in 8 hours. Due to a leak at the bottom, it takes 12 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank?