*MENTAL MATHEMATICS* You saw a T-shirt of *shs 10000,* since you don't have cash, you borrow?

... *sh5000* from your dad and *sh5000* from your Mom.

Now you have *sh10000*

You purchase a T-shirt for *sh9700* and left with *sh300* change.

You return *sh100* to your dad and *sh100* to your mom and keep the *sh100* for yourself.

Now you owe your mom *Sh4900* and your dad *sh4900.* Added together *(sh4900+sh4900=sh9800)* plus your *Sh100=sh9900.* Where is the missing *sh100???*

Please give me the answer.