You are writing a practice quiz that has 5 questions. Each question has 4 responses. If you answer all 5 multiple-choice questions, what is the probability that you will get at least 1 question correct?

If you want at least 1 correct, then the only outcome you do not want is to have all questions incorrect. So, determine the probability of choosing all incorrect. Because each question has 4 possible responses and only 1 correct answer, you have a 3-out-of-4 chance of getting each question incorrect.

The probability of getting at least one question correct is or about 76.3%.


Using a graphic organizer such as a Venn diagram or probability tree diagram can be helpful in solving at least problems. The next example in your textbook explores this option.


Read pages 194-197 Example 2 in your textbook, Principles of Mathematics 12 .

Complete the Your Turn questions on page 197 (a & b) for practice related to at least problems.

Click here to verify your answers .


At the beginning of this Training Camp , you watched a video depicting how to draw a probability tree diagram. Read Example 7 to review this skill for dependent events before you continue with the remainder of the lesson.