Type : MCQ
An empty vessel is connected with 3 pipes A, B, and C. Pipe A is opened first and can fill the vessel in 4 minutes. Pipe B is opened after 1 minute and can fill an empty vessel in 2 minutes. Outlet pipe C is opened after another 1 minute and can empty the entire vessel in 1 minute. After how much time from the start is the vessel empty for the first time?