Did you solve it? Are you a match for the world’s smartest teen?
The solution to today’s puzzle Earlier today I set you the following puzzle, suggested by Briton Alex Chui, the most successful ever candidate at the International Mathematical Olympiad. Last month Alex, who is a pupil at Tonbridge School in Kent, became the first person to win a medal at the olympiad for seven years in a row. Bravo! Continue reading...
The puzzle presented by British teenager Alex Chui, a champion at the International Mathematical Olympiad, challenges the solver to fill a 3x3 grid with positive whole numbers. The key condition is that the product of the numbers in each row and column should equal 30. To solve this, Alex emphasizes the importance of understanding the prime factors of 30, which are 2, 3, and 5.
He notes that each row and column must contain exactly one 2, one 3, and one 5. For the placement of the 2s, there are six possibilities. This is calculated by choosing the position of the 2 in the first row (3 ways), the second row (2 ways), and the third row has only one option left (1 way). The same logic applies to the placement of the 3s and 5s.
Since each full grid represents a unique arrangement of these prime factors, the total number of possible grid arrangements is the product of the individual placements - 6 (for 2s) multiplied by 6 (for 3s) multiplied by 6 (for 5s), totaling 216 ways to fill the grid. An example of one possible solution is provided in the puzzle.
Written by urgent.news from Guardian Science's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
