Exercise 13 Page 848

We select a chip randomly from a bag that contains 3 blue chips, 6 black chips, 2 green chips, and 4 red chips. We are asked to find the probability that we select a blue chip or a black chip. Note that we cannot choose a blue chip and a black chip at the same time. Therefore, these events are mutually exclusive. If events A and B are mutually exclusive, then the probability that either A or B occurs is the sum of the probability of A occurring and the probability of B occurring. P( Aor B)=P( A)+ P( B)

In order to find the desired probability, we will find the probability that we select a blue chip and the probability that we select a black chip one at a time. Let's start by calculating the probability of choosing a blue chip.

Out of 15 chips in the bag, there are 3 blue chips. P( blue chip)= 3/15=1/5 Next, we will calculate the probability of choosing a black chip.

Out of 15 chips in the bag, there are 6 black chips. P( black chip)= 6/15=2/5 Finally, we can find the desired probability by adding the obtained probabilities.

P(blue chip or black chip)

Substitute

P(A or B)= P(A) + P(B)

P(blue chip)+ P(black chip)

SubstituteII

P(blue chip)= 1/5, P(black chip)= 2/5

1/5+ 2/5

AddFrac

Add fractions

3/5

Therefore, the probability P(blue chip or black chip) is equal to 35.