Math
posted by StuartKess .
Mr smith flight took off at Vancouver at local time 1335. The flight was bounded for Sydney via hongkong. After 16.5h flight, mr smith reached hongkong at 1505 local time on the same day. The plane took off again after 2h 20min. The plane landed in sydney at local time 0245 the next day. If the time in Sydney is 2h ahead of hongkong, find
(a) the time difference between Vancouver and hongkong
(b) the flight time from hongkong to Sydney

Let the time between V and HK be x hours
15:05 + x  13:36 = 16:30
1:30 + x = 16:30 ,  (15:0513:36 = 14:6513:36 = 1:30 )
x = 15:00
so the time between Vancouver and HongKong is 15 hrs.
For the second leg, the plane took off from HK at
17:25 ,  (15:05+2:20 = 17:25)
which would have been 19:25 Sydney time
but the Sydney time was 02:45 the next day,
or 26:45 based on the previous day
length of last flight = 26:45  19:25 = 7:20
so the flight from HK to S took 7:20 hrs 
How do I get 13:36 ?