Mathematics > Standard Multiple Choice
Read the following SAT test question and then click on a button to select your answer.
Ten cars containing a total of 32 people passed through a checkpoint. If none of these cars contained more than 4 people, what is the greatest possible number of these cars that could have contained exactly 2 people?
(A) One
(B) Two
(C) Three
(D) Four
(E) Five
正确答案：D
答案解析：
It could not be true that each of the ten cars contained exactly 2 people, as this would give a total of only 20. If nine of the cars contained exactly 2 people, the remaining car could have no more than 4 people, for a total of only 22. Continuing in the same way, a pattern develops. If eight of the cars contained exactly 2 people, the remaining two cars could have no more than 4 people each, for a total of only 24. If seven of the cars contained exactly 2 people, the total number of people could be only 26. From the pattern, you can see that if four of the cars contained exactly 2people, and the remaining six cars contained the maximum of 4 people, the total number would be 32, as given in the question. Therefore, at most four of the ten cars could have contained exactly 2 people.
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