Pipe A can fill a tank in 10 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 choice:
A) 18 B) 27 C) 98 D) 27 E) 48
Let the pipe B be closed after x minutes.   30/10 - x/24 = 1 =&gt; x/24 = 30/10 - 1= 
<gadget id="calculator">30/10 - 1</gadget>
<output>2</output>
2=&gt; x = 2 * 24= 
<gadget id="calculator">2 * 24</gadget>
<output>48</output>
48.   Answer:48
<result>E</result>
Pipe A can fill a tank in 10 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?