At 17 39, Cathy started driving at 72 km/h from her home to a bakery 42 km away. She was at the bakery for 1 h 15 min.
- What time did she leave the bakery?
- After leaving the bakery, Cathy drove back along the same route and took 36 min to reach home. What was her average speed, in km/h, for the journey home?