Essentials Chapter 6 question help

[Bee49]

Could someone please explain how to answer this for me? Many thanks. (from 6B Essentials textbook)

The journey between two towns by one route consists of 233 km by rail followed by
126 km by sea. By a second route the journey consists of 405 km by rail followed by
39 km by sea. If the time taken for the first route is 50 minutes longer than for the second
route, and travelling by rail is 25 km/h faster than travelling by sea, find the average speed
by rail and the average speed by sea.

[duquesne9995]

This is Q15, isn't it?

[Bee49]

Yes, it is! I managed to solve it shortly afterwards, and did it the same way you did Thanks!