Probability is the measure of how likely an event is to occur, expressed as a number between 0 (impossible) and 1 (certain). It is calculated as the ratio of favorable outcomes to total possible outcomes when all outcomes are equally likely.
Probability is a way of putting a number on chance. Flipping heads? That's 0.5 (half the time). Rolling a 6 on a die? That's 61 (one out of six possible outcomes). It's like asking 'if we did this many times, what fraction would this outcome happen?'
Showing a random 20 of 50 problems.
Example 1
easy
A fair six-sided die is rolled. What is the probability of rolling an even number?
Example 2
medium
From 1 to 50, find the probability that a randomly chosen number is a perfect square.
Example 3
hard
A spinner has 5 sections labeled 1,2,3,4,5. The probability of landing on each section is proportional to its label. What is the probability of landing on 3?
Example 4
hard
A bag has 4 red, 6 green, and 10 blue marbles. Find P(not green).
Example 5
medium
A die is rolled. What is the probability of rolling a prime number?
Example 6
medium
A standard die is rolled. What is the probability of rolling a number less than 5?
Example 7
hard
A spinner has 8 sections, 3 red and 5 blue. After 80 spins, red came up 24 times. Compute both the theoretical and experimental probability of red.
Example 8
medium
A card is drawn from a 52-card deck. What is the probability of drawing a red face card (J, Q, K of hearts or diamonds)?
Example 9
easy
A coin is flipped. What is the probability of tails?
Example 10
easy
P(rain)=0.4. What is P(no rain)?
Example 11
easy
Probabilities are numbers in what range?
Example 12
medium
A die is rolled. What is the probability of rolling an odd number?
Example 13
medium
A bag has tickets numbered 1 to 30. What is the probability of drawing a multiple of 7?
Example 14
easy
A bag has 3 red and 2 blue marbles. What is the probability of drawing a red marble?One marble drawn from a bag of 3 red and 2 blue
Example 15
medium
From a deck of 52 cards, what is the probability of drawing a card that is either red or a queen?
Example 16
hard
A bag has 20 marbles: 5 red, 8 blue, 7 green. What is the probability of drawing a marble that is red OR blue?
Example 17
medium
A spinner has sections colored red (probability 0.25), blue (0.35), and green. What is the probability of green?
Example 18
easy
What is the probability of an impossible event?
Example 19
medium
A bag has marbles numbered 1 to 20. What is the probability of drawing a multiple of 5?
Example 20
easy
A fair die is rolled. What is the probability of rolling a 6?