Exams, Combining Prayers And Tayammum
Perhaps you can perform wudu before you get on the train. If that’s not possible and you can’t perform wudu on the train either then you always have the option of performing tayyamum. As Umer stated, you can combine Zuhr and Asr in your situation as well. Similarly, Maghrib and Isha can be combined if a need arises.
Are we talking about possibility or ease? It’s possible to do anything. But it would be a whole lot easier to combine the prayers