Question

We have 5 multiple choice questions with four choices with two correct answers each. If we just randomly guess on each of the 5 questions, how many questions do you expect to choose correct answers? (No need to be integer for the number of questions) Select one: a. 3.5 questions b. 2.5 questions c. 3 questions d. 1 question

Answer 1

b. 2.5 questions

Explanation:

If we consider one question:

Total number of choices: 4

Total number of correct choices: 2

Then the probability of randomly guessing one question correct is:

`(2)/(4)`

Therefore, expected number of correct answer in one question is
`(2)/(4)=0.5`

As a Result, expected number of correct answers of 5 questions is =5×0.5=2.5