You all end up crossing the bridge a few minutes before the wild animals arrive to the other side of the bridge. You set a big fire and the animals decide to go away. You and your family can now continue the trip. You are all surrounded by beautiful plants and get distracted admiring all this beauty. All of a sudden a poisonous snake bites your father, Chris. You know that if he does not get the antidote, he will die. Luckily, you have a cure. Your father needs to take two kinds of pills. One pill from a yellow bottle and one pill from a blue bottle together at the same time every day for 5 days. You only have one yellow bottle with exactly 5 pills and one blue bottle, also with 5 pills. If Chris takes more or less than the proper dose, he will die. For example, if he takes more than one pill from the yellow bottle at one time, or if he only takes a pill from the blue bottle and don’t take the pill from the yellow bottle, he dies. Moreover, there will be no transportation to go back home until your trip is over in a week so there is no way you can get extra pills.
On the first day, everything goes well. You carefully pour one pill from the yellow bottle into your palm and carefully pour one pill from the blue bottle into your palm, and your father swallows them together. On the next day, you pour one pill from the yellow bottle into your palm, but you aren’t careful, and you pour two pills from the blue bottle into your palm! Now you have three pills in your palm. And here’s the bad news: the two types of pills are absolutely indistinguishable. How do you help your father survive?
When you finally solve this puzzle, the tribal people are very thankful and invite you to spend the night in their village. They let you stay in a 50x 50x 50 ft3 very cool tree house which sits on four 100-foot tall trees. The next morning, you all wake up hoping to continue your trip but the chief of the tribe wants you to stay at least 10 more days because they have many more ancient puzzles they want you to solve for them. You try to explain to them that you cannot stay that long but they don’t want to hear your reasons and lock you up in the tree house to force you to stay. So you decide to escape that very night. There is an open window at the corner of the room, near the floor. There is a strong hook near the window, so if you tied a 100-foot rope to the hook you can climb out through the window. The trees are not accessible through the window. There are two 50-foot ropes, each stuck in the center of the ceiling one foot apart. You can climb ropes and tie knots well, and you have a sharp knife. You have no other tools to use (and you can’t use clothes). The rope is strong enough to hold your weight and every member of your family’s weight, but not if it is cut lengthwise. You can survive a fall of no more than 10 feet. How do you get out?
After a couple of days in the ship, you go ashore and spend a night in a hotel before taking the bus home. Your room is actually a duplex. Upstairs, there is a room with a light bulb that is turned off. It turns out that the switch to turn it on is on the first floor. But there are three switches and only one of them controls the bulb on the second floor. After so many days of solving interesting puzzles and problems, your sister challenges you to discover which switch controls the bulb, but you are only allowed to go upstairs once. How do you do it? (no fancy strings, telescopes, etc. allowed. You cannot see the upstairs room from downstairs. The light bulbs are standard 100-watt bulbs)