Having problem with 'find text position', help me!

I’m not English user, sorry for my bad language

I’m having problem with ‘Find Text Position’

Here is my condition:
(1) Scanned a page about mathematics, and i also did ‘OCR’ this page with Acrobat -> I have a OCRed page!

(2) The result from ‘Get Full Text’ or ‘Screen Scrapping’, it shows texts! (eventhough it was not good quality, All I need was ‘Question Number’ and it gets me ‘Question Number’)

(3) I need to know position of ‘Question Number’, so I did ‘Find Text Position’. But it can’t find text… why? and I also did ‘Text Exist’, ‘Text OCR Exist’, they didn’t find text neither!

please help me!!

Can you share a sample so that I can help you

img_1
[This is a line of OCRed page that i want to find]
I’m really sorry cannot uploading the whole page because it is the part of published book


[This is the result of Screen Scrapping]
as you can see, it found texts…

img_3
[I typed in the number i want to find with ‘Find Text Position’]

img_4
[It shows me Activity cannot find text…]

I’m very thankful to your good will, please understand that i can’t upload the whole page i’m very sorry …