How do you use the probability rules?

Question

There are 95 thriller movies on Netflix. Amy likes 60 of them. What is the probability that the next fifteen movies played are films that Amy likes? 

There are fifteen available toppings for a pizza. If four toppings come with each pizza, what is the probability that those toppings are sausage, mushrooms, onions, and olives?

In a lottery, you choose five numbers from 1 through 45. What is the probability that the numbers you choose are the winning ones? 

Answer 1

Goody, another three fer.

a) We can't tell because the rest of the population of movies available isn't known, nor are the other likes of Amy other than thriller movies known. It is a story of the great unknown.

b) Let us assume that that the selecting any of the 15 is at random and that the probability of selecting any one is the same for each. Further let us assume that no two toppings are repeated. Order does not matter, and no repeating so there are 4C4 ways (1) to select S,M,O,and O, and a total of 15C4 ways to select any 4 random toppings (without replacement). P(t = SMOO) is .0073

c) There is only one way of selecting 5 specified numbers (order does not matter) out of 5 (i.e. fully specified selection). There are 45C5 different combinations of 5 balls (no replacement and order does not mater. so the odds are 1 in 1,221,759.