Answer:
4.35pm is the later time, both buses were together back at the depot.
Reasons;
As bus b did not return his return route until 35 minute after departure.
We can say this was a return route taking 35 minute as the question does not point out length of time getting back. We therefore state it is a return route in the workings to explain how we found the answer.
Step-by-step explanation:
4.00 + 0.35 = 4.35 = b
4.00 + 0.15 = 4.15 = a
4.35 is the later time.
