Four number-pairs are given, out of which three are alike in a certain manner and one is different. Choose the different number pair.

Solution

The logic followed here is as follows: The square of each digit of the 1st number is added together and then, the resultant is multiplied by 2 to obtain the 2nd number. 486: 232 →  [2 × {(4)² + (8)²+ (6)² }] = [2 × {16 + 64 + 36}]= [2 × 116] = 232 752: 156 →  [2 × {(7)² + (5)² + (2)² }] = [2 × {49 + 25 + 4}]= [2 × 78] = 156 543: 100 → [2 × {(5)² + (4)² + (3)² }] = [2 × {25 + 16 + 9}]= [2 × 50] = 100 581: 182 → [2 × {(5)² + (8)² + (1)² }] = [2 × {25 + 64 + 1}]= [2 × 90] = 180 ≠ 182