Level 1 · Question 1

Archived question

Try the question in your own editor, then check your output below.

THE QUESTION

Text from the official booklet. Refer to the PDF for original mathematical notation, formatting, and linked input files. Printed samples and inputs are reproduced as published.

Create a function that finds all prime numbers in a list and returns them as a set.
Input:
list = [7458, 7501, 8443, 7907, 6977, 1264, 9272, 7269, 3814, 2455, 1970,
2288, 4614, 9718, 6523, 1631, 3631, 7023, 8101, 4201, 7261, 6448, 5611, 7907,
1953, 9959, 7499, 9256, 4684, 4071, 1621, 4510, 1509, 1810, 6660, 2507, 8566,
5466, 2939, 6516, 7238, 1813, 8567, 2548, 9779, 1556, 6753, 7321, 6049, 6395]

CHECK YOUR ANSWER

Try your answer.

Run your program in your own editor, then paste its output below. This checks the stated output; it does not assess your full program. Practice attempts do not affect competition scores.

Reveal worked answer

Your output · one valid answer

[1621, 2939, 3631, 4201, 6977, 7321, 7499, 7907, 8101, 8443]

Test divisors through the square root of each value, discard composites and remove duplicates. Any set order is accepted.

Reveal supplied answer

From the supplied Intermediate answer key. Outputs are reproduced as provided.

Expected output

{6977, 7907, 2939, 8101, 4201, 7499, 3631, 1621, 7321, 8443}

Source: GIC 2025 Intermediate Questions and the supplied Intermediate answer key, March 2025 archive.