Amit is going to guess on all 20 questions of his multiple-choice test. Each question on the test has 4 answer options, and only one is correct.What is the best prediction for the number of questions that Amit will answer correctly?Choose 1 answer:(A) Exactly 5 questions(B) Close to 5 questions but probably not exactly 5 questions(C) Exactly 80 questions(D) Close to 80 questions but probably not exactly 80 questions
Q. Amit is going to guess on all 20 questions of his multiple-choice test. Each question on the test has 4 answer options, and only one is correct.What is the best prediction for the number of questions that Amit will answer correctly?Choose 1 answer:(A) Exactly 5 questions(B) Close to 5 questions but probably not exactly 5 questions(C) Exactly 80 questions(D) Close to 80 questions but probably not exactly 80 questions
Understand the problem: Understand the problem.Amit is guessing on a multiple-choice test with 20 questions. Each question has 4 answer options, and only one option is correct. We need to predict how many questions Amit will answer correctly by guessing.
Calculate probability: Calculate the probability of guessing a question correctly. Since there are 4 answer options and only one is correct, the probability of guessing a question correctly is 1 out of 4, or 41.
Use probability to predict: Use the probability to predict the number of correct answers.To find the expected number of correct answers, multiply the probability of getting a question right 41 by the total number of questions 20.Expected number of correct answers = 41×20
Perform the calculation: Perform the calculation.Expected number of correct answers = 0.25×20Expected number of correct answers = 5
Interpret the result: Interpret the result.The calculation shows that the best prediction for the number of questions Amit will answer correctly is 5. However, since guessing introduces variability, it is unlikely to be exactly 5. The prediction is that it will be close to 5 questions.