You can't just add figures from the question arbitrarily and expect it to add to 100. It makes no sense.
For example: Amount Paid by Parents+Amount owed to Parents = 98+98 = 196, where did the extra 96 come from?
Your sum is:
[Liability] Amount still owed to Parents
+ [Asset] Amount still owned by you
+ [Transfer] amount previously paid to parents (which is already accounted for)
Why would you think this should be 100? Adding your liabilities to your assets is nonsensical.
I think the wiki page explains it pretty clearly:
https://en.wikipedia.org/wiki/Missing_dollar_riddleHope this helped,
R. Baber.