Concept: probability

Question 1)

The data represents the results for a test for a certain disease. Assume one individual from the group is randomly selected. Find the probability of getting someone who tests positive, given that he or she has the disease.

The individual actually had the disease

              Yes No

Positive 121 15

Negative 39 125

Question 2)

Two cards are chosen at random without replacement from a deck of 52 cards containing 4 kings. What is the probability of selecting two kings from the deck without replacement?

Question 3)

A box contains 23 yellow, 27 green and 37 red jelly beans. If 15 jelly beans are selected at random, what is the probability that:

a) Exactly 10 are yellow?

b) Exactly 10 are yellow and 4 are green?

c) At least one is yellow?