Question

A jar contains 8 green, 5 red, 4 blue, and 3 black marbles.once a marble is selected, it is not replaced. find each probability.
1) p(two green marbles)
2) p(two black marbles)
3) p(a red marble and then a blue marble)
4) p(a black marble then a green marble)
5) p(two marbles that are not red)
6) p(two marbles that are neither blue nor green)

7) a family has two children, both of whom are boys. what is the probability that the next child will be born a boy?

Answer 1

what you need to do is use a tree chart of some sort to figure it out it should something like this

Answer 2

then you just go off those selecting each of the next possible colors.
p.s. it will take up some room