Hi

1)

A="Both balls are blue"

B="Both balls are green"

2)

I calculated the probability that a book was torn, and took 1 minus that probability.

3) Since the coin is fair, it is a 50-50 shot that either of them will go first. But given the probabilites here it doesnt matter who goes first, it is always 50-50 for a draw. So...

Answer:

4)

A="The bus is not late"

B="It does not rain"

Then by Bayes Theorem:

Here we calculated "Given that the bus was not late, what is the probability of it not raining". So therefore we must take to get the probability of it raining.

I hope these are right, Iīm confident mrFantastic or anyone more experienced will soon give their input as well.