There are 10 socks of each of the following colours in a drawer: blue, green, red, yellow & white, for a total of 50 socks. If the socks are all mixed up in the drawer (i.e. not in pairs or any other grouping), and it is dark, what is the minimum number of socks you must pull from the drawer in order to be certain you have at least one pair?

A man leaves home one night and drives over a mile to meet a friend for a drink. When the man arrives home, the clock shows a time only five minutes later than when he left. The clock is working perfectly. How is this possible?