Three of the following four are alike in a certain way and thus form a group. Which is the one that does NOT belong to that group?
(1) 11 - 120
(2) 13 - 168
(3) 15 - 224
(4) 18 - 325
Show answer & explanation
Correct answer: A
Explanation
The correct answer is Option 1 i.e. 4.
Logic: [(First no.)2- 1] = second no.
Option (1) 11 - 120 →
= [(11)2-1] = 121 - 1 = 120
Option (2) 13 - 168 →
= [(13)2-1] = 169 - 1 = 168
Option (3) 15 - 224 →
= [(15)2-1] = 225 - 1 = 224
Option (4) 18 - 325 →
= [(18)2-1] = 324 - 1 = 323 ≠ second no.
Thus, 18 - 325 is an odd one out as it does not follow the above logic.
Hence, 18 - 325 is the correct answer.