Probability 7th grade

Front

What is probability?

Back

Probability is a measure of how likely an event is to occur, expressed as a number between 0 and 1, where 0 means the event cannot happen and 1 means the event is certain to happen.

Front

What is the probability of selecting an odd number from the numbers 1 to 15?

Back

The probability is 8/15, as there are 8 odd numbers (1, 3, 5, 7, 9, 11, 13, 15) out of 15 total numbers.

Front

If a number cube is rolled 24 times, how do you predict the number of unsuccessful rolls if the player wins by rolling a 4?

Back

You can predict 20 unsuccessful rolls, as the probability of rolling a 4 is 1/6, so the expected number of successful rolls is 4 (1/6 of 24), leading to 20 unsuccessful rolls.

Front

What is the probability of drawing two yellow marbles from a bag containing 3 green and 2 yellow marbles without replacement?

Back

The probability is 1/10. The probability of drawing the first yellow marble is 2/5, and the second yellow marble is 1/4, so (2/5) * (1/4) = 1/10.

Front

How do you estimate the number of students wearing spirit wear at a school assembly if 3 out of 10 students were wearing it?

Back

You can estimate 120 students wearing spirit wear at an assembly of 400 students, as (3/10) * 400 = 120.

Front

What is the probability of both coins landing heads up when two coins are flipped?

Back

The probability is 1/4, as there are 4 possible outcomes (HH, HT, TH, TT) and only 1 favorable outcome (HH).

Front

What is a sample space in probability?

Back

A sample space is the set of all possible outcomes of a probability experiment.

Front

What is an event in probability?

Back

An event is a specific outcome or a set of outcomes from a probability experiment.

Front

What does it mean if an event is independent?

Back

An event is independent if the outcome of one event does not affect the outcome of another event.

Front

What is the formula for calculating the probability of an event?

Back

The probability of an event is calculated as P(E) = Number of favorable outcomes / Total number of possible outcomes.