Sohan was travelling on one side of the express way with a constant speed of 80 kmph in his car while Mohan was travelling with a constant speed of 50 kmph in the opposite direction. When they crossed each other, Sohan decided to take a U-turn and meet him. But before taking a U turn, Sohan had to travel for another 12 minutes. How long will it take for Sohan to meet Mohan? [Assume time taken by Sohan to take U turn is negligible]