Probability of the complement of an event

Front

What is the probability of the complement of an event?

Back

The probability of the complement of an event A, denoted as P(A'), is calculated as P(A') = 1 - P(A). It represents the likelihood that event A does not occur.

Front

If the probability of an event A is 0.4, what is the probability of its complement A'?

Back

P(A') = 1 - P(A) = 1 - 0.4 = 0.6.

Front

In a box of 45 stamps, if 18 are 60-sen stamps, how many are not 60-sen stamps?

Back

27 stamps are not 60-sen stamps.

Front

If 60% of cars at a toll plaza are Toyotas, what is the probability that a randomly picked car is not a Toyota?

Back

The probability is 40% or 2/5.

Front

During a rainy season, if the probability of rain on a day is 3/5, how many days in a 30-day month are expected to be without rain?

Back

Expected days without rain = 30 * (1 - 3/5) = 12 days.

Front

A bag contains 45 marbles, 17 of which are white. If the probability of picking a blue marble is 2/9, what is the probability of picking a marble that is not green?

Back

The probability of picking a marble that is not green is 3/5.

Front

In rolling a fair die, if A is the event of rolling a multiple of 3, what is P(A')?

Back

P(A') = 2/3.

Front

Define the term 'complementary events' in probability.

Back

Complementary events are two outcomes of an event that are mutually exclusive and exhaustive, meaning one must occur if the other does not.

Front

What is the formula to find the expected number of days without an event occurring?

Back

Expected number of days without an event = Total days * (1 - Probability of the event).

Front

If the probability of an event is 0.75, what is the probability of its complement?

Back

P(A') = 1 - 0.75 = 0.25.