The conditional probability formula is

which gives

Then, for the first question, we get

which gives

Now, for the second question, we know that, for independent events

then, we have

which gives

Now, for question 3, we know that, when the events are dependent and mutually non-exclusive

By substituting the given values, we have

Finally, for the 4th question, we have

which gives

In summary, the solutions are:
Question 1:

Question 2:

Question 3:

Question 4:
