Joe has to take two quizzes tomorrow. He has only enough time to study for one of them.
• The science quiz has 7 true-or-false questions.
• The English quiz has 5 multiple-choice questions.
Joe calculates the probability that he will get each question correct by guessing.
Science
English
To get 100% correct:
Answer 7 of 7 correctiv
Answer 5 of 5 correctiv
P(guess is correct)
0.5
0.25
Joe will study for the quiz on which he is likely to do worse by guessing. Which quiz should he study for?
• A. Science, because the probability of getting all questions correct is
(0.008), which is lower than for English (0.125).
• B. English, because the probability of getting all questions correct is 0.001, which is lower than for science (0.008).
• c. English, because the probability of getting all questions correct is
(0.125), which is lower than for science (0.5).
• D. Science, because he must get more questions correct.