Thanks Keith. It's a nav question (flight planning)
Ref CAP697 MEP 3.6
Cruise PA 18000ft OAT +5
Airfield PA 4000ft OAT +20
Wind component in descent +40kt
What are the fuel, time and distance (NGM)
I got fuel 8-2 = 6USG, time 19-4 = 15mins, distance 52-11 + 15/60*40 = 51NGM
i.e. cover more distance in same time due to tailwind.