Select the number that can replace the question mark (?) in the following series.
11, 14, 31, 14, 16, 34, 17, 18, 37, ?, 20, ?

11, 14, 31, 14, 16, 34, 17, 18, 37, ?, 20, ?

In the series, the first(11), fourth(14), seventh(17), and tenth(?) numbers are having a common difference of 3.

So the tenth number = 17+3 = 20

11, 14, 31, 14, 16, 34, 17, 18, 37, ?, 20, ?

In the series, the second(14), fifth(16), eighth(18), and eleventh(20) numbers are having a common difference of 2.

11, 14, 31, 14, 16, 34, 17, 18, 37, ?, 20, ?

In the series, the third(31), sixth(34), ninth(37), and twelveth(?) numbers are having a common difference of 3.

So the twelveth number = 37+3 = 40

Hence 20 and 30 will come in place of question mark respectively.