+25 You borrow $50 from your mom and $50 from your dad to buy a T-shirt.
The T-shirt costs $97 and you receive $3 change.
You give $1 to your mom, $1 to your dad and keep $1 to yourself.
Now you owe $49 to your mother $49 to your father and the $1 you kept to yourself.
$49+$49+$1 = $99.
Where did the last dollar go?
+2353 You're welcome.
You could've googled it though, it's a pretty well known math mistake to trick people. 
If you like, have a look at my comment in this one; (2=1) http://web2.0calc.com/questions/i-need-help-with-this-ecvation
It's another faulty riddle...
+2353 You're making the wrong addition here,
The money you need to put together to pay your parents back is
49+49-1 = 97, because you already have 1 dollar.
Because you keep 1 dollar to yourself and only give 2 dollars to your parents
the money you still need to pay back to your parents is $98 (of which you already have 1 dollar)
The t-shirt shop has 97 dollars, your mum has 1 dollar, your father has 1 dollar and you have 1 dollar which totals 100 dollars.
To summarize, there is no missing dollar.
Reinout
+2353 You're welcome.
You could've googled it though, it's a pretty well known math mistake to trick people.
If you like, have a look at my comment in this one; (2=1) http://web2.0calc.com/questions/i-need-help-with-this-ecvation
It's another faulty riddle...
