What should come in place of the question mark (?) in the given series? 10 13 19 28 40 ?

The correct answer is 55.

To find the missing number in the given series, let us analyze the pattern of differences between consecutive terms:

First term: 10
Second term: 13
Third term: 19
Fourth term: 28
Fifth term: 40
Sixth term: ?

Let us calculate the difference between consecutive numbers:

13 - 10 = 3

19 - 13 = 6

28 - 19 = 9

40 - 28 = 12

We can observe that the differences form an increasing sequence of multiples of 3: 3, 6, 9, 12, ...

Following this pattern, the next difference to be added to the fifth term (40) is 15 (since 12 + 3 = 15).

Therefore, the missing number (?) is:

$40+15=55$

Thus, 55 is the correct number to replace the question mark in the series.