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

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
`(1)/(5)`

i.e. 1 out of 5 questions is correct

Using binomial distribution

where n=40 p=
`(1)/(5)`

mean of binomial distribution is np

therefore mean of no of correct answers=
`40* (1)/(5)`

=8