Question

In a multiple choice quiz there are 5 questions and 4 choices for each question (a, b, c, d). Robin has not studied for the quiz at all, and decides to randomly guess the answers. What is the probability that

Answer 1

`Pr = 0.140625`

Explanation:

Given

`n = 5` --- questions

`options = 4` ---- a, b, c or d

Required

The probability that 1st correct question is the 3rd

The probability of selecting the right answer is:

`p = (1)/(options)`

`p = (1)/(4)`

`p = 0.25`

Using complements, we have:

`q = 1-p`

`q = 1-0.25`

`q = 0.75` --- probability of selecting the wrong answer

The required probability is represented as:

Pr = First is wrong * Second is wrong * Third is correct

`Pr = q * q * p`

This gives

`Pr = 0.75 * 0.75 * 0.25`

`Pr = 0.140625`