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. . . .
Can you explain why every year must contain at least one Friday the thirteenth?
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?
Can you rank these sets of quantities in order, from smallest to largest? Can you provide convincing evidence for your rankings?
What size square corners should be cut from a square piece of paper to make a box with the largest possible volume?