PSAT Math Multiple-Choice Question 158: Answer and Explanation

Question: 158

If a patient in the study is selected at random, which of the following is closest to the probability that the patient will have a recovery time of more than 6 months?

• A. 0.28
• B. 0.40
• C. 0.52
• D. 0.81

Correct Answer: C

Explanation:

C

The question asks for the probability a patient in the study selected at random will have a recovery time of more than 6 months. Probability is defined as . Read the table carefully to find the right numbers to set up the probability. Because the question states that a patient in the study is selected at random, the total # of possible outcomes is the total number of patients in the study, which is 485. Because the question asks for the probability that the patient will have a recovery time of more than 6 months, the # of outcomes that fit the requirement is the total number of patients with a recovery time of more than 6 months. Make sure to include both those in experimental physical therapy and those in conventional physical therapy to get a total of 112 + 140 = 252. Therefore, the probability is . The question says is closest to, so select the closest choice. The correct answer is (C).