Select the correct option that will fill in the blank and complete the series.
5,……,10,19,35,60

Let's analyze the differences between consecutive terms of the given series:
5,?,10,19,35,60

Let the missing term be x.
The differences between consecutive terms are:
First difference: x−5
Second difference: 10−x
Third difference: 19−10=9
Fourth difference: 35−19=16
Fifth difference: 60−35=25

Notice that the known differences (9,16,25) are consecutive perfect squares:

9=3
2

16=4
2

25=5
2

Following this backward pattern, the previous differences should be:
Second difference =2
2
=4
First difference =1
2
=1

Testing this:
If First difference =1, then:

x−5=1⟹x=6
Let's verify with the second difference:

10−x=10−6=4=2
2

This matches the pattern perfectly. Thus, the missing number is 6.