if a train leaves Leeds at 6.40 a.m. and arrives in London at 8.55 a.m. How long does the journey take?

think about it

6:40 to 8:40 That's 2 hours

8:40 to 8:55 that is 15 minutes. 

hence 2 hours and 15 minutes.  

Assuming they're in the same time zone - and I think they are...... 2 hrs 15 min