for 2nd question, since each car is driven by its owner, there is only 1 way to arrange the 3 drivers.

to keep the calculation simple, we can completely disregard the 3 drivers and just calculate base on 9 people instead of 12.

Thank you so much !! So easy to understand it now ! :)))

Hi Sir, i would appreciate it if you could help me with my latest question if possible... Thank you so much !