Each of the questions below consists of a question and two statements numbered…

2023

Each of the questions below consists of a question and two statements numbered I and II below it. You have to decide whether the data provided in the statements are sufficient to answer the question. Read both the statements and give an answer.

How many students are there in the row of students facing south?

I. Kalyani is 9th to the left of Ketaki, who is 16th from the right end. The rank of Kalyani from the left end = 11.

II. Sukumar is sixth to the left of Nandu, who is eighth from the right end and seventeenth from the left end.

  1. A.

    The data in statement I alone are sufficient to answer the question, while the data in statement II alone are not sufficient to answer the question.

  2. B.

    The data in statement II alone are sufficient to answer the question, while the data in statement I alone are not sufficient to answer the question.

  3. C.

    The data in either statement I alone or statement II alone are sufficient to answer the question.

  4. D.

    The data given in both statements I and II together are not sufficient to answer the question.

Show answer & explanation

Correct answer: C

Concept

In a single row, if some student's rank from the left end and rank from the right end are both known (directly or via a stated relation to another student), then Total students = (rank from left) + (rank from right) - 1. A statement is sufficient for this question type if it lets you pin down some student's rank from BOTH ends.

Statement I

  1. Kalyani's rank from the left end is stated directly as 11.

  2. Kalyani is 9th to the left of Ketaki. Using the standard reading of this phrase for row positions (Ketaki's rank from the left end = Kalyani's rank from the left end + 9), Ketaki's rank from the left end = 11 + 9 = 20.

  3. Ketaki's rank from the right end is stated directly as 16.

  4. Total students = 20 + 16 - 1 = 35.

  5. Statement I alone fixes a total (35), so it is sufficient by itself.

Statement II

  1. Nandu's rank from the left end is stated directly as 17.

  2. Nandu's rank from the right end is stated directly as 8.

  3. Total students = 17 + 8 - 1 = 24.

  4. This uses only the two ranks stated directly for Nandu; the extra detail about Sukumar being sixth to the left of Nandu is not even needed.

  5. Statement II alone fixes the total (24), so it is sufficient by itself.

Cross-check

Statement I involves Kalyani and Ketaki, while Statement II involves Sukumar and Nandu; each statement is judged only on its own numbers. Statement I's working gives a total of 35 and Statement II's working gives a total of 24 - these need not agree with each other, since sufficiency is judged separately for each statement, not by combining them into one shared configuration.

Since EACH statement alone is enough to compute a total, the data in either statement I alone or statement II alone are sufficient to answer the question.

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