Question

A quiz has 1 true-false question and 2 multiple choice questions that each have 4 answers. What is the probability that someone guessing all 3 answers will get 100% on the quiz?

Answer 1

`3.125%`

Explanation:

The probability of getting the true-false question correct is `1/2`, since there are two options (true and false) and only one of them is correct.

The probability of getting the first multiple choice question correct is `1/4`, since there are four choices and only one correct answer.

The probability of getting the second multiple choice question correct is also `1/4`.

The probability of getting all of the questions correct (that is, getting the first question correct and the second question correct and the third question correct) is `1/2 * 1/4 * 1/4`, since and denotes multiplication.

`1/2 * 1/4 * 1/4 = 1/32`

`1/32 = 0.03125 = 3.125%`

So, there is a `3.125%` chance that you will get a one-hundred by guessing.