At 11 40, Shiyun started driving at 78 km/h from her home to a bakery 39 km away. She was at the bakery for 1 h 36 min.
- What time did she leave the bakery?
- After leaving the bakery, Shiyun drove back along the same route and took 20 min to reach home. What was her average speed, in km/h, for the journey home?