其它
A talk show has two $$30$$-minute parts and has few commercials between them. The TV show started at $$1:50$$ and ended at $$3:00$$. How many minutes long were the commercials in total? 
Overseas Competition->Knowledge Point->Combinatorics->Time Problem
From $$1:50$$ to $$3:00$$ is $$1$$ h $$10$$ min, and two $$30$$-minute parts = $$60$$ min. $$1$$ hr $$10$$ min = $$70$$ min, and $$70 - 60 = 10$$ min. 