Select the set in which the numbers are related in the same

Solution

The logic followed here is: In each set, the absolute difference between the square of the 1st and 2nd number is the 3rd number. i.e., in (A, B, C) : C = |B² - A²|

In (9, 11, 40) = |11² - 9²| = |121 - 81| = 40

In (15, 7, 176) = |15² - 7²| = |225 - 49| = 176

In option '1', (8, 10, 38) = |10² - 8²| = |100 - 64| = 36 ≠ 38

In option '2', (13, 5, 140) = |13² - 5²| = |169 - 25| = 144 ≠ 140

In option '3', (6, 4, 20) = |6² - 4²| = |36 - 16| = 20

In option '4', (12, 11, 26) = |12² - 11²| = |144 - 121| = 23 ≠ 26