Three brainteasers: You have a gold bar and you need to pay an employee once a day for a week. You can cut it twice only. How do you pay him each day of the week for all seven days? There are three barrels with fruit in them. One has strawberries, one has bananas, and the last has a mixture of both. They're all labeled incorrectly. How can you figure out which barrel contains which fruit with 100% certainty? You have 27 black socks, 18 dark gray socks, and 9 navy blue socks in a drawer. The room is completely dark and you cannot see anything. What is the least number of socks you need to grab to guarantee you have a pair of black or dark gray socks? You have ten bags of 100 gold coins and a scale. Nine of the bags have fools gold (which weigh 1.1g each coin), and the last bag is real gold (1g/coin). You can only weigh ONE TIME total. How do you find the real bag of gold with 100% certainty?
