Question

Suppose you're taking an Honors Algebra 1 multiple choice test. The test consists of 40 questions, each having 5 options. If you guess at all 40 questions, what is the mean of the number of correct answers?

Answer 1

Answer:8

Step-by-step explanation:

We have given test consists of 40 multiple choice questions having five options for each question.

Suppose there is one correct answer to each question

therefore probabilty of getting a correct answer on making a guess is $\frac{1}{5}$

i.e. 1 out of 5 questions is correct

Using binomial distribution

where n=40 p=$\frac{1}{5}$

mean of binomial distribution is np

therefore mean of no of correct answers=$40\times \frac{1}{5}$

                                                                    =8