Yesterday’s Question:
You have 10 black and 10 white socks
tucked away in the top drawer of your dresser.
The room is totally dark and the electricity
is temporarily off due to an ice storm.
You would like to get a matching pair of socks.
How many socks will need to take out of the
drawer before you will be guaranteed to have a
matching pair of socks?
Answer:
The answer is 3. Once you pull out two socks
you will have one of three combinations:
* two black socks or
* two white socks or
* one black and one white sock.
The next sock you pull out of the drawer
will assure you of having a matching pair
of either white or black socks if you don’t
already have a matching pair.
Today’s Problem
How many 9’s do you encounter when you
start counting at 1 and count to 100?