Choose the one which is different from the rest three.

The correct answer is Option (3) → 831

The odd number out is found from a property that three of the numbers share. Here it is the product of the digits:

• Option (1) 314 — \(3\times1\times4=12\)

• Option (2) 162 — \(1\times6\times2=12\)

• Option (3) 831 — \(8\times3\times1=24\), the only product that is not 12, so 831 is the odd one out.

• Option (4) 232 — \(2\times3\times2=12\)

Note: The original NTA paper printed Option (1) as 431. NTA’s answer key accepted it as well as Option (3), because 431 is the only prime number of the four (\(162=2\times81\), \(831=3\times277\), \(232=8\times29\)), which makes it the odd one out by another rule. For the benefit of students and to ensure a single answer, Option (1) has been changed to 314, an even number and so not prime, whose digits multiply to 12 like the others. Four numbers, two odd ones out: even NTA’s key could not pick just one.