Sometime during every hour the minute hand lies directly above the
hour hand. At what time between 4 and 5 o'clock does this happen?
Christmas trees are planted in a rectangular array of 10 rows and
12 columns. The farmer chooses the shortest tree in each of the
columns... the tallest tree from each of the rows ... Which is. . . .
This month there is a Friday the thirteenth and this year there are
three. Can you explain why every year must contain at least one
Friday the thirteenth?