Throughout history, a wide variety of items have served as money. These include gold, silver, large stone wheels, tobacco, beer, dog teeth, porpoise teeth, cattle, metal coins, paper bills, and checks. All of these types of money should...

In this riddle, some endangered fish species are being transported by water and a storm causes them to be thrown overboard. Your task is to devise a way to rescue them. The video provides some pointers on how to approach the problem....