The number that least fits this set: {324, 441, 97, 64} is ________. A. 324 B. 441 C. 97 D. 64

GATE 2016 · General Aptitude · Odd One Out · easy

Answer: C. 97

1. Verify each number as a perfect square: 324: sqrt(324) = 18. Check: 18 x 18 = 324. Perfect square. 441: sqrt(441) = 21. Check: 21 x 21 = 441. Perfect square. 64: sqrt(64) = 8. Check: 8 x 8 = 64. Perfect square. 97: 9^2 = 81 < 97 < 100 = 10^2. No integer square root. Not a perfect square.
2. Identify the odd one out: 324, 441, and 64 are all perfect squares. 97 is the only number in the set that is not a perfect square, so it least fits the set.