Task-oriented dialogue about: train

I'm looking for a train on Sunday that leaves after 17:15.
What are your departure and arrival destinations?
I'll be leaving from cambridge and heading to stansted airport.
Ok there are 7 choices. Is there a particular time you'd like to arrive at your destination?
not really, it just needs to leave after 17:15.
There are plenty of choices starting at 17:40 and leaving every hour onwards. Do you want me to book it?
Yes, book it for 7 people at 17:40
Booking was made, ref number is 6QWLFWW5! Do you need anything more?
thats all, see ya!
have a safe trip, bye.