Introduction To

Basic Compound Probability

Making Compound Probability Simple

You roll a number cube numbered from 1 to 6.You then spin a spinner with 3 sections each with a different color. The spinner has the colors orange, gray, and pink.

What is the probability of rolling the following?(2, 4, 1, 5, or 3 and orange)

You roll a cube which has the numbers 13, 7, 8, 11, 8, and 13 on it. You then spin a spinner which has 8 sections. The letters on the spinner are G, H, E, G, H, C, E, and E.

What is the probability of (H and 13).

Compound ProbabilityThe likelihood that a compound event will

occur; for example: P(A or B); P(A and B and C)

Theory that the Probability that two independent events will occur.

Examples – Working Through ItYou enter a spelling bee at your school.

You have found that you can correctly spell words 90% of the time.

1) What is the probability that you spell the first 5 words correctly?

2) What is the probability that you correctly spell the first 4 and then miss-spell the 5th word?

3) What is the probability that you win the contest by spelling all 25 words correctly?

The Atlanta Braves pitching staff has 5 left-handers and 8 right-handers.

If 2 pitchers are selected at random to warm up, what is the probability that at least one of them is right-hander?