Eureka Primary School is having their Sports Day. Each activity is $$45$$-minute long, and there is a $$20$$-minute break between each activity. The entire duration of Sports Day, from the start of the first activity to the end of the last activity, is $$8$$ hours and $$20$$ minutes. How many activities are there in Sports Day? 
Overseas Competition->Knowledge Point->Combinatorics->Time Problem