Three of the following four triads are alike in a certain way as they are formed by performing the same mathematical operations among themselves and thus form a group. Which triad does NOT belong to that group?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 7: 15: 49.
The logic used here is:
Option 1: 11: 21: 121
11 × 2 = 22
22 - 1 = 21
112 = 121
This follows the logic.
Option 2: 7: 15: 49
7 × 2 = 14
14 - 1 = 13
72 = 49
This does not follow the logic.
Hence, option 2 is the odd one out.