Taps A and B can fill a bucket in 12 minutes and 15 minutes respectively. If both are opened and A is closed after 4minutes, how much further time would it take for B to fill the bucket?	Choose the correct choice from the following answers
A) 6 min.	B) 4 min.	C) 5 min.	D) 3 min.	E) 2 min.
Explanation:   Part filled in 4 minutes =   4∗(1/12+1/15)=4∗9/60=3/5   Remaining part =1−3/5=2/5   =&gt;1/15:2/5=1:X   =&gt;X=6   =&gt;X=6 min.   So it will take further 6 min. to fill the bucket.   Option 6 min.
<result>A</result>
Taps A and B can fill a bucket in 12 minutes and 15 minutes respectively. If both are opened and A is closed after 4minutes, how much further time would it take for B to fill the bucket?