An urn contains 25 red balls and 15 blue balls. Two are chosen at random, one after the other, without replacement.
a. Use a tree diagram to help calculate the following probabilities: the probability that both bal1 are red, the probability that the first ball is red and the second is not, the probability that the first ball is not red and the second is red, the probability that neither ball is red.
b. What is the probability that the second hail is red?
c.What is the probability that at least one of the balls is red?
To use a tree diagram to calculate that both balls are red, the probability that the first ball is red and the second is not, the probability that the first ball is not red and the second is red, the probability that neither ball is red.
Given information:
An urn contains
Calculation:
Let
Total balls
Now calculate the probabilities on first draw
Now on the second draw if the red ball is already taken out, number of red balls will be
What is the probability that the second ball is red?
To find the probability that at least one of the balls is red.