Pipe A can fill a tank in 9 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:  A) 36  B) 88  C) 18  D) 26  E) 12
Let the leak can empty the full tank in x hours 1/9 - 1/x = 1/12   =&gt; 1/x = 1/9 - 1/12 = 1/12   =&gt; x = 36. 36nswer:36
<result>A</result>
Pipe A can fill a tank in 9 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?