A five-question quiz is taken in which the first and second questions have four answer choices, the third and fourth questions have three answer choices, and the last question has five answer choices. If a student randomly marks an answer for each question, what is the expected number of questions he will answer correctly?

A. 0.27

B. 0.96

C. 1.00

D. 1.37

Option D). 1.37

Step-by-step explanation:

According to the question, a five-question quiz is taken in which the first and second questions have four answer choices, the third and fourth questions have three answer choices, and the last question has five answer choices. If a student randomly marks an answer for each question, what is the expected number of questions he will answer correctly?

If the first 2 questions have four options, then the probability of getting the 2 of them correctly will be 2/4

The same applies for the third and fourth question that has 3 options for the person to choose from.

The probability of getting the third and fourth questions correct is 2/3

And lastly, for the last question which as an option of 5 to choose from, the probability of getting that one question correct out of five options is 1/5

If a student randomly marks an answer for each question, the expected number of questions he will answer correctly will be

2/4 + 2/3 + 1/5

= 1.37