A woman lives in a Tall building thirty-six floors high and served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?
What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?
There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?
There was a blind man. He had four socks in his drawer either black or white. He opened it and took out two socks. Now the probability that it was a pair of white socks is 1/2.
Can you find out the probability that he had taken out a pair of black socks ?
