Maths Olympiad Prep

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, 2024

Combinatorics Difficulty 5.0 AIME, harder Find the answer United Kingdom

There are nn distinct lines in the plane. One of these lines intersects exactly 55 of the nn lines, another of these intersects exactly 99 of the nn lines, and yet another intersects exactly 1111 of them. Which of the following is the smallest possible value of nn?

(A) 1212 (B) 1313 (C) 1414 (D) 2525 (E) 2828

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