Two pipes A,B can fill a tank in 24 min. and 32 min. respectively. If both the pipes are opened simultaneously, after how much time B should be closed so that the tank is full in 18 min.?
Options:
A) 6 B) 7 C) 8 D) 9 E) 5
work done by A =&gt; 18/24   work done by B =&gt; x/32   18/24 + x/32 = 1   3/4 + x/32=1   24+x=32 =&gt; x=8   after 8 min b should be closed   ANSWER:8
<result>C</result>
Two pipes A,B can fill a tank in 24 min. and 32 min. respectively. If both the pipes are opened simultaneously, after how much time B should be closed so that the tank is full in 18 min.?