3 identical taps can fill a tank at the speed of 10 litre/per minute each. They are opened simultaneously when the tank is empty at 10:00 am and stopped at 11:40 am. An pipe with a emptying speed of 30 litre per minute is started at 12:00 pm. At what time will it empty the tank completely?

12:30 pm 12:40 pm 1:00 pm 1:40 pm

1:40 pm

The correct answer is Option (4) → 1:40 pm