HELP PLEASE THIS IS EASY MATH BUT I LITERALLY DONT UNDERSTAND IT

Airline passengers arrive randomly and independently at the passenger-screening facility at a major international airport. the mean arrival rate is 10 passengers per minutes. compute the following probabilities. p(x = 4) p(x > 11)

Gretchen is setting up for a banquet. she has 300 chairs and needs to distribute them evenly among t tables. how many chairs should she put at each table? write your answer as an expression.

Somone me i want to know what 18 hours out of 24 hours in a fraction