Pls help me :< Sarah went to the movies. After the movies , she wanted to ride the bus home. The B6 and the B9 buses both stop at the movies outside Sarahs house.
Hint☟
-A B9 and B6 bus both left the movies at 3pm.
-B9 buses are scheduled to leave the movies every 12 minutes.
- B6 buses are scheduled to leave the movies every 9 minutes.

If the buses ran on schedule, what is the next time both of the buses will leave together.

pls show some sort of work :>