question_answer

Two pipes A and B can fill a tank in 6 hours and 3 hours respectively. Both the pipes are opened simultaneously and pipe A is closed after 1 hours. Find the time taken by B to fill the remaining part of the tank (in hours).

A)  1                                

B)  \[1\frac{1}{2}\]

C)  2                                

D)  \[2\,\,\frac{1}{2}\]

E)  None of these