I'm posting one puzzle, riddle, math, or statistical problem a day. Try to answer each one and post your answers in the comments section. I'll post the answer the next day. Even if you have the same answer as someone else, feel free to put up your answer, too!
Monday, February 06, 2006
Nail in the tree
When Sandy was six years old she hammered a nail into her favorite tree to mark her height. Ten years later she returned to see how much higher the nail was. If the tree grew by 5 centimeters each year, how much higher would the nail be?