If you answer this I will pass my exam please help

This doesn’t make sense to me it’s supposed to be lcm ( least common multiple )

Vinay constructed this spinner based on the population of teachers at his school according to vinays model what is the probability that he will have a male history teacher two years in a row

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ac=26 and ch=8, find bh.