Practice Basic Probability in Statistics
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
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 \frac{1}{6} (one out of six possible outcomes). It's like asking 'if we did this many times, what fraction would this outcome happen?'
Example 1
easyA bag contains 3 red, 5 blue, and 2 green marbles. What is the probability of drawing a blue marble?
Example 2
easyA fair six-sided die is rolled. What is the probability of rolling an even number?
Example 3
easyA spinner has 8 equal sections numbered 1–8. What is the probability of landing on a number greater than 5?
Example 4
easyA card numbered 1 through 10 is chosen at random. What is the probability that the number is prime?