## Additive law

Example: 2 cars, each with a 60% chance of starting. What are the chances that at least one of them starts?

P (A U B) = P(A) + P(B) – P(A Intersection B)

P = .6 + .6 – (.6*.6) = 1.2 – .36 = .84

## Mutually Exclusive Events

Mutually exclusive events are things cannot both be true.

## Compound Events

Events that are chained together in a row.

### Compounded Mutually Exclusive Events

For example, what is the probability of rolling one 6 sided die and getting either a 3 or a 4?

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

P (3 or 4) = P(3) + P(4) = 1/6 + 1/6 = 1/3 = 33%

### Independent Events

For example, what is the probability of rolling one 6 sided die twice and getting a 3 on the first roll and a 4 on the second roll?

Since the roll of the second die can be anything – no matter what happens on the first roll – they are considered independent events.

P (A and B) = P(A) * P(B)

P (3 and 4) = P(3) * P(4) = 1/6 * 1/6 = 1/36 = 2.7%

YOU WERE TO ROLL A SIGLE DIE 10 TIMES,WHAT WOULD THE RESULTS OF EACH ROLL WOULD

BE

A. MUTUALLY EXCLUSIVE OF THE OTHER NINE ROLLS

B. PROPORTIONAL TO THE OTHER NINE ROLLS

C. DEPENDENT UPON THE OTHER NINE ROLLS

D. INDEPENDENT OF THE OTHER NINE ROLLS.