Four pairs of numbers are given. Three are alike in a certain way while one is different. Choose the odd one out.
Show answer & explanation
Correct answer: D
Explanation
The pattern followed in the given pairs is:
Second number = (First number)2 − 2
• 12 : 142 → 122 − 2 = 144 − 2 = 142
• 15 : 223 → 152 − 2 = 225 − 2 = 223
• 18 : 322 → 182 − 2 = 324 − 2 = 322
• 21 : 441 → 212 = 441 ≠ 212 − 2 (which is 439)
Hence, 21 : 441 is the odd one out.