Probability Flashcard (Addition & Multiplication Rules!)

Front

What is the probability of choosing a black marble from a bag containing 4 black marbles and 2 white marbles?

Back

The probability is 4/6 or 2/3.

Front

If you choose a black marble and do not replace it, what is the probability of then choosing a white marble?

Back

The probability is 2/5.

Front

What is the probability of choosing either a black or white marble from a bag with 4 black and 2 white marbles?

Back

The probability is 1 (or 100%) since all marbles are either black or white.

Front

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

Back

The probability that it will NOT rain is 70%.

Front

What does it mean for two events to be mutually exclusive?

Back

Two events are mutually exclusive if they cannot occur at the same time.

Front

What is the probability of drawing a spade or a red card from a standard deck of cards?

Back

The probability is 26/52 or 1/2.

Front

What does it mean for two events to be independent?

Back

Two events are independent if the occurrence of one does not affect the occurrence of the other.

Front

If you draw one card from a deck and replace it before drawing again, are the events independent or dependent?

Back

The events are independent.

Front

What is the formula for calculating the probability of two independent events A and B occurring?

Back

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

Front

What is the formula for calculating the probability of two mutually exclusive events A and B occurring?

Back

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