In a row of students facing north, Pooja is 9th from the left end and Suresh is 7th from the right end. Exactly 3 students stand between Pooja and Suresh. What is the minimum possible number of students in the row?

11Correct answerYour answer15Correct answerYour answer16Correct answerYour answer19Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Case 1, Suresh to the right of Pooja: Suresh is at $9 + 3 + 1 = 13$ from the left, so the row has $13 + 7 - 1 = 19$ students.
Case 2, Suresh to the left of Pooja: Suresh is at $9 - 3 - 1 = 5$ from the left, so the row has $5 + 7 - 1 = 11$ students.
Check case 2: Pooja at 9 is inside a row of 11, so it is valid. The minimum is 11.

Worth noting

The stem does not say which of the two is nearer the left end, so both cases are allowed. The minimum, 11, comes from the case where their positions cross (Suresh to the left of Pooja); 19 is the no-crossing case. When a question asks for the minimum, always test the crossing case too.

Concept: Minimum row length using the crossing case
Typical timeTypical: 115 s
Your timeYours: —

The rule this testsPosition in a row

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Ten questions from Ranking and Ordering, at your own pace.

In a row of students facing north, Pooja is 9th from the left end and Suresh is 7th from the right end. Exactly 3 students stand between Pooja and Suresh. What is the minimum possible number of students in the row?

Explanation