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

Solution

The pattern followed here is: The square of sum of digits of 1st number is added to 1st number to obtain the 2nd number. In option 'a', 343: 443 → [(3 + 4 + 3) ² + 343] = [(10)² + 343] = [100 + 343] = 443 In option 'c', 572: 768 → [(5 + 7 + 2)² + 572] = [(14)² + 572] = [196 + 572] = 768 In option 'd', 448: 704 → [(4 + 4 + 8)² + 448] = [(16)² + 448] = [256 + 448] = 704 All combination of number follows the above pattern except for: In option 'b', 765: 979 → [(7 + 6 + 5)² + 765] = [(18)² + 765] = [324 + 765] = 1089 ≠ 979