In a school, there are a total of 88 students in three sections, A, B, and C.…

2024

In a school, there are a total of 88 students in three sections, A, B, and C. Each section has a different number of students. Section B has the maximum number of students among the three. How many students are seated in section B? I) One of the sections has two students fewer than section B. II) One of the sections has 23 students.

  1. A.

    Statement I alone is sufficient to answer the question.

  2. B.

    Statement II alone is sufficient to answer the question.

  3. C.

    Both statements I and II together are sufficient to answer the question.

  4. D.

    Even both statements I and II together are not sufficient to answer the question.

Attempted by 1 students.

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Correct answer: D

A pair of data-sufficiency statements is sufficient only when applying it, together with every stated constraint, pins down exactly one valid value for what is asked. Here, the constraints are: the three sections' student counts are distinct positive integers that add up to 88, and section B holds the largest count of the three.

  1. Statement I alone: it says one section has two students fewer than B (that section = B minus 2). This only fixes a relationship between two sections; it gives no actual count, so B cannot be found from this alone.

  2. Statement II alone: it says one section has 23 students. Since B is the largest of three distinct positive integers summing to 88, B itself cannot be 23 - if B were 23, the other two sections would each have to be smaller and distinct, so at most 22 and 21, giving a total of at most 66, short of 88. So the 23-student section must be one of the non-B sections, but this alone still leaves many different valid values for B (many different distinct pairs for the other non-B section and B can sum with 23 to 88), so B cannot be pinned down from this statement alone.

  3. Combining both statements: the '23-student' section and the 'B minus 2' section can relate to the three sections A, B, C in only three possible ways.

  4. Case (i) - the same section is both 'B minus 2' and '23': then B minus 2 = 23, so B = 25, and the third section = 88 minus 25 minus 23 = 40. But 40 is greater than 25, so that section would exceed B, contradicting that B is the maximum. Invalid.

  5. Case (ii) - 'B minus 2' and '23' are two different sections, with B as the third: then B + (B minus 2) + 23 = 88, giving 2B = 67, so B = 33.5, not a whole number of students. Invalid.

  6. Case (iii) - B itself is the section with 23 students: then the other section is B minus 2 = 21, and the third section = 88 minus 23 minus 21 = 44. But 44 is greater than 23, so that section would exceed B again, contradicting that B is the maximum. Invalid.

  7. Every possible way of applying both clues together either produces a fractional student count or breaks the rule that B is the largest section. So no consistent value of B exists even when both statements are combined.

Checking directly: is there any set of three distinct positive integers summing to 88, with the largest one equal to B, one other section equal to B minus 2, and one section equal to 23? The three cases above are exhaustive, since the '23' section must be the 'B minus 2' section, a different section, or B itself, and each case fails, confirming there is no valid assignment.

Since neither statement alone, nor both together, fix a valid value for B, the correct choice is: even both statements together are not sufficient to answer the question.

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