Insert the missing number.

2, 6, 12, 20, 30, 42, 56, (....)

Here the given series 222, 271, 308, 332, 348, 357 follows a pattern that

222

222 + 49  271

271 + 36 = 307 (NOT 308)

307 + 25 = 332

332 + 16 = 348

348 + 9 = 357

Hence, the odd man in the fiven number series is 308.

The given series is 1/2, 1, 3/2, 6, 5/2, 3

1/2

1/2 + 1/2 = 1

1 + 1/2 = 3/2

3/2 + 1/2 = 2 (Not 6)

2 + 1/2 = 5/2

5/2 + 1/2 = 3

Hence, the odd man in the given number series is 6.

The given number series is 720, 732, 708, 742, 696

720

720 + 12 = 732

732 - 24 = 708

708 + 36 = 744 (Not 742)

744 - 48 = 696

Hence, the odd man in the given number series is 742.

Here the given series is 123 112 133 112 143

It follows a pattern that,

123

123 - 11 = 112

112 + 21 = 133

133 - 31 = 102 (not 122)

102 + 41 = 143

Hence, the odd man in the given number sequence is 122 instead of 102.