DRDO Multi tasking staff Model paper 4

The correct answer is option 2 i.e. 13
Abhisekh is sitting 15th position from the left end.
Arnab is 17‌th position from the right end.
Case 1:
14 (Abhisekh)--------(Arnab) 16.
We won't get any answer from this diagram.
Case 2:

As per the question, we should consider the minimum possible case, so there are at least two persons to the right of Abhisekh.
So, the number of students between Abhisekh and Arnab is 13
EXPLANATION:
Here,
we get, between value (13) = Abhisekh's positional value (15 - 2 = 13)
Here, in this case "Overlapping"occurs.
Hence, the correct answer is 13.