A drawer has red socks and black socks. You take two socks out at random and the probability that both are red is exactly 1/2. How many socks are in the drawer?
A drawer has red socks and black socks. You take two socks out at random and the probability that both are red is exactly 1/2. How many socks are in the drawer?
Well this probability is:
Trial and error shows that is a solution, but is
it the only solution?