Probability (Addition & Multiplication Rules!)

Front

What is the probability of an event?

Back

The probability of an event is a measure of the likelihood that the event will occur, expressed as a number between 0 and 1, where 0 indicates impossibility and 1 indicates certainty.

Front

What is the addition rule of probability?

Back

The addition rule states that the probability of the occurrence of at least one of two events is equal to the sum of their individual probabilities minus the probability of their intersection.

Front

What is the multiplication rule of probability?

Back

The multiplication rule states that the probability of the occurrence of two independent events is the product of their individual probabilities.

Front

How do you calculate the probability of flipping a coin and getting tails three times in a row?

Back

The probability of getting tails in one flip is 1/2. For three flips, the probability is (1/2) * (1/2) * (1/2) = 1/8.

Front

What is the probability of drawing a card from a standard deck and getting a spade?

Back

There are 13 spades in a standard deck of 52 cards, so the probability is 13/52 or 1/4.

Front

What is the probability of rolling a die and getting an even number?

Back

There are three even numbers (2, 4, 6) on a die, so the probability is 3/6 or 1/2.

Front

What does it mean for events to be mutually exclusive?

Back

Mutually exclusive events are events that cannot occur at the same time. For example, rolling a 3 and rolling a 4 on a single die roll are mutually exclusive.

Front

What is the probability of NOT an event occurring?

Back

The probability of an event not occurring is equal to 1 minus the probability of the event occurring.

Front

If the probability of rain today is 30%, what is the probability that it will not rain?

Back

The probability that it will not rain is 1 - 0.30 = 0.70 or 70%.

Front

What is the probability of choosing a black or white marble from a bag containing 2 black, 1 white, and 2 red marbles?

Back

The total number of marbles is 5. The probability of choosing a black or white marble is (2 black + 1 white) / 5 = 3/5.