Riddle: A man phoned his daughter to ask her to buy a few things he needed for a trip. He told her she would find enough dollar bills for the purchase in an envolope on his desk. She found the note with 98 written on it.
In the store she bought $90 dollars worth of things, but when it was time to pay she not only did have $8 left over but she was short.
By how much and why?
Answer: (A). $4. She had read 86 upside down.
(B). Turn 9 upside down and exchange it with the 8. Both columms will add to 18.