A Puzzle A Day: 2026-04-01

Correct: 289

Let's break down the clues to find the secret three-digit number: 1. **It is a perfect square:** We need to list three-digit perfect squares. These range from 10² = 100 to 31² = 961. The choices provided are all perfect squares: 144 (12²), 256 (16²), 289 (17²), 676 (26²). 2. **The sum of its digits is a prime number:** * For 144: 1 + 4 + 4 = 9. (9 is not a prime number, so 144 is eliminated.) * For 256: 2 + 5 + 6 = 13. (13 is a prime number. 256 is a candidate.) * For 289: 2 + 8 + 9 = 19. (19 is a prime number. 289 is a candidate.) * For 676: 6 + 7 + 6 = 19. (19 is a prime number. 676 is a candidate.) Our remaining candidates are 256, 289, and 676. 3. **The product of its digits is also a perfect square:** * For 256: 2 × 5 × 6 = 60. (60 is not a perfect square, so 256 is eliminated.) * For 289: 2 × 8 × 9 = 144. (144 is a perfect square, as 12² = 144. 289 remains a candidate.) * For 676: 6 × 7 × 6 = 252. (252 is not a perfect square, so 676 is eliminated.) The only number that satisfies all three conditions is 289.