What type of random variable would I use for question 1? Number 2 is also giving me trouble.

1. Tiny Town Airlines has an 18 seat plane, but they've sold 20 tickets in an effort to increase prots. Suppose each passenger shows up with a probability of 90% indepen- dently of one another. a) What is the probability that the airline will not be able to provide every passenger who shows up with a seat? (Hint: what kind of random variable can you use to model this?) b) What is the expected number of passengers to arrive for the ight? c) Find the probability that there is exactly 1 empty seat on the plane. 2. (Challenge, not required). A Kinder egg is a chocolate candy that contains a hidden toy. Suppose there are 5 possible toys one can obtain from a Kinder egg, and each toy is equally likely of being in any particular Kinder egg. On average, how many Kinder eggs does one need to purchase to obtain to have a complete collection of all 5 toys