Pipe A can fill a tank in 2 hours. Due to a leak at the bottom, it takes 3 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank? Choose one
A) 10 B) 9 C) 7 D) 6 E) 5
Let the leak can empty the full tank in x hours 1/2 - 1/x = 1/3   =&gt; 1/x = 1/2 - 1/3 = (3 - 2)/6 = 1/6   =&gt; x = 6.   Answer: 6
<result>D</result>
Pipe A can fill a tank in 2 hours. Due to a leak at the bottom, it takes 3 hours for the pipe A to fill the tank. In what time can the leak alone empty the full tank?