Which number is not a rational number?

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)

In priyas math class there are 10 boys and 15 girls. what is the ratio of boys to girls in priyas math class? express your answer as a decimal

Aladder that is 20ft long is leaning against the side of a building. if the angle formed between the ladder and the ground is 75 degrees how far is the bottom of the from the base of the building?