Question 455551
You used half of the time to arrive at 2625.
500*2.5+550*2.5=2625

The misleading part is half of the journey. 
Is that half by time or distance?
550*x=d 
500*y=d
since the distances are the same
550x=500y
x+y=5
x = 50/21, y = 55/21, z = 55000/21
x=2.38095,   y=2.61905,   z=2619.05