USAAAO 2026, I кръг — Задача 6

USAAAO 2026 - First Round · 9 февруари 2026 г.

Problem writers

Problem writers: Srihari (Hari) Balaji, Vincent Bian, Ferdinand, Hagan Hensley, Elizabeth Lee, Joe McCarty, Lucas Pinheiro, Feodor Yevtushenko

Условие

The following figure is used for questions 4, 5, and 6.

You are stranded on a remote island somewhere on Earth, at an unknown date and time (in the $21^{\mathrm{st}}$ century). You look up and see the night sky.

(For avoidance of doubt, the illuminated side of the Moon is on the left.)

Which of the following is the best estimate of the time of day (relative to local solar noon)?

(a) 8:00 PM

(b) 10:00 PM

(c) 12:00 AM

(d) 2:00 AM

(e) 4:00 AM

Отговори

Решение

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Оригинал в Архива: usaaao_first_exam_2026.pdf · официални решения: usaaao_first_exam_solutions_2026.pdf