A test consists of 10 true or false questions. To pass the test a student must answer at least eight questions correctly. If the student guesses on each question, what is the probability that the student will pass the test?
A)0.055
B)0.8
C)0.20
D)0.08

Question

Quizplus · Accepted Answer

The probability of passing the test (answering at least 8 out of 10 questions correctly) by guessing can be calculated using the binomial probability formula. The probability of success (getting a question right) is 0.5 for each question since it's a true or false question. The probabilities of getting exactly 8, 9, or 10 questions right need to be calculated and then summed up. The calculations yield a probability of approximately 0.055.

A Test Consists of 10 True or False Questions