You should put this in Desmos, it’s online for graphing.
The least common multiple of 12 and 15 is 60. Every hour the tours leave at the same time.
The tours will leave at the same time at 11:30, 12:30, ...
2000. Because if you add the 2 it will make 1200, 2+8 is 10 so you carry the 1, and 3+9 is 12 then you add the 1 you got from 10 and you have 13. then you add 1+1 and get 2 and add the 1 you got from 13 so there you have it.
