You are taking a 10-question multiple-choice Statistics test Each question has four answer choices and you guess on each question because you came to class totally unprepared What is the probabilit?

Answer 1

Assuming the placement of each correct answer (i.e. a, b, c, or d) is random, the probability of answer B being correct will be 25% for each question, independent of each other (the placement of an answer on question 2 shouldn't depend on the placement in question 1 - again, assuming no bias of test author). Hence, on average, you should get 2.5 questions right out of 10 if you were to take the test an infinite number of times.