Pipe A can fill a tank in 8 minutes and pipe B cam empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes?
Choose the correct answer:
A) 18  B) 27  C) 98  D) 27  E) 66
Let the pipe B be closed after x minutes.   30/8 - x/24 = 1 =&gt; x/24 = 30/8 - 1 = 11/4   =&gt; x = 11/4 * 24= 
<gadget id="calculator">11/4 * 24</gadget>
<output>66</output>
66.   Answer:66
<result>E</result>
Pipe A can fill a tank in 8 minutes and pipe B cam empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes?