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

Answer 1

1.37

Explanation:

1

Answer 2

If a five-question quiz is taken in which the first and second questions have four answer choices the third and fourth. The expected number of questions the student will answer correctly is 1.37.

What is the expected number of questions?

The probability of answering each of these questions correctly = 1/4

The probability of answering each of these questions correctly= 1/3

The probability of answering this question correctly = 1/5

Expected number of questions answered correctly:

Expected number of questions answered correctly = (1/4) * 2 + (1/3) * 2 + (1/5) * 1

= 1/2 + 2/3 + 1/5

= 15/30 + 20/30 + 6/30

= 41/30

= 1.3667

=1.37

Therefore the expected number of questions the student will answer correctly is 1.37.