If it's not too late to point out the questions in the paper are fairly simple all you need is a little background on something called mathematical linguistics.Not in much detail as you'll be learning it in the IIIT-H 5 year course itself.
And yeah 2000 rupees are worth it if it gives you a chance to study at an institute like IIIT-H because believe me when I say it if you do your CS Degree from that institute you'll be one of the best in the subject.
Also here is a link of a short course on mathematical linguistics(7-8 hours):
@Shubham_Bhagat I made it when I was in 6th XD
Just type Anirudh Goel on google play you'll get a list of apps all of them are mine
Also, a quick hint(on a lighter note) for the graph question to the people who are trying integration to solve it, let's go back to class 5th
add all the values in the plotted graph on the x-axis
Now, let's divide it by 7,i.e, 10.5/7 =1.5(ans)
Did you see what I did just take average its simple?
Another hint this paper is more about computer science than about applied mathematics in JEE so you need to think it like a programmer and programmers are lazy they try to use the shortest and the least cumbersome method like I do.