I've always enjoyed asking my children tricky or trick questions - just to see how carefully they are listening and to encourage them to think outside the box. Whenever I hear interesting questions, I always remember them and add them to my collection. For example, I remember a question on the University of Cambridge entrance exam. It gave the heat transfer coefficient of glass, the size of a window, the temperature outside (32 degrees) and the temperature inside (72 degrees), and asked how much energy is needed to keep the room at that temperature. When you did the math, the answer was something like 700 megawatts. But that wasn't the real answer (because that's the output of a typical power station!). Students had to realize that the temperature gets cooler near the windown, so the real temperature difference is not 40 degrees but maybe 2 or 3 degrees. That was the purpose of the question. One of my favorites revolved around the river Fal (one of the big rivers of Cornwall). Every day, about 20 barges would leave the mining area upstream with a heavy load of copper ore, sail around the coast, and unload at Plymouth. Late afternoon, they would return empty. One day, the last of the barges, while fully loaded, sank. Unfortunately, it sank in a very difficult place and blocked all the bigger ships and liners that moored in the river. The authorities tried all they could to bring the barge to the surface, even using the biggest and strongest crane in the country. But it was to no avail: The barge was stuck fast in the mud at the bottom of the river. So, the government issued a plea and offered a large reward to anyone who could rescue the situation. Within 12 hours, one of the local fishermen was a very rich man. How did he raise the sunken barge to the surface? Another of my favorites involves three solid bricks of the same size. Give them to the child and also give them a wooden ruler. They have 60 seconds to measure the exact distance from the front, bottom, left corner of a brick to the back, top, right corner. Some give up, and others try to use Pythagoras - but the key is that you've given them three bricks. Place them side by side, and then remove the middle brick. In this case, the answer involves measuring something that's not there - not something that is there. Is anyone else odd like me in enjoying trick and tricky questions of this type?
I've given the answers to two of the questions. For the record, the answer to the other question is as follows. The local fisherman collected large chains from around the port area. When the tide was out, he had local men dive down and attach one end of each chain to the sunken barge. Then, he had them attach the other end of each chain to an empty barge on the river. Now, with the tide out, ten barges were attached by chains to the sunken barge. All he had to do now was wait. As the tide came in, the water level rose. Archimedes' Principle started to take effect as the barges on the surface were raised by the tide - whereas, due to the attached chains, the sunken barge reacted by pulling the floating barges down. Newton's Law (action equals reaction) kicked in, meaning that the force due to Archimedes was applied upwards to the sunken barge - but there were ten barges pulling up. Eventually, the force became extreme enough to loosen the sunken barge from the mud. I really like this story because it explains graphically how some principles of physics work - Archimedes' Principle, Newton's Laws, the cause of two tides per day, and so on. Incidentally, it's also a great allegory for the power of God when we simply do our bit (attach the chains) and allow him to work through us (the tide coming in).
As another example of a question that forces you to think, I remember one from my final college exam for physics (even though the question was more about chemistry than physics). It showed a periodic table with no atomic numbers or chemical symbols present; however, the letters a, b, c and so on appeared in some parts of the table. The questions were something like "(a) exhibits sublimation at room temperature". Realizing that an 'a' appeared in the right-most column where iodine sits revealed the answer: 'a' equals iodine, and so on. The trick, though, was that the periodic table had eleven entries in the middle section and not ten. It was a deliberate error, and students had to be smart enough to realize this and deduce from answers to the questions which column shouldn't be there. In my answers, I noted that column '6' (or whatever) was the unwanted column. I learned later that I received extra credit for noting this. So, again, it's a question that forces students to think outside the box, realize when something is amiss, and be confident enough to demonstrate initiative and point out the error. It's like being Sherlock Holmes instead of Dr. Watson when learning a new subject.
I think those type of questions are good, but I am not patient enough usually to wait for the answer. I have often looked in those type of books at the store and thought about how something could work out for about 30 seconds before I look up the answer in the back. I know, I know the point of these things is to think and try and keep trying for at least a little while....
I didn't even understand the majority of the questions! I think you really need to have a very technically wired brain for stuff like this.
Years ago, Britain used to have an 11+ plus exam. When my cousin sat the exam, one of the questions was as follows: A truck (8'6" tall) was being driven along a country road when it encountered a low bridge. On the bridge was a sign that only vehicles 8'5" or less could pass beneath it. Unfortunately, there was no other route, so the driver had to figure out how to proceed. What did he do to make it to his destination?
LOL.....Gonna let my oldest read these. We're studying Logic this year, wondering if she could figure them out!
The answer: let air out of the tires to lower the bed and thus lower the vehicle. Wouldn't take much air loss to lower the vehicle one inch. The driver can air them back up at the next truck stop.
Some questions force students to listen carefully to the question and not to get distracted by unnecessary detail. I'm sure many of you have seen the following problem: You are driving a local bus. At the start of the journey, 10 girls and 4 boys climb onto the bus. At the first stop, half the girls get off and 2 boys get on. At the second stop, 3 girls get on and half the boys get off. At the third stop, one more girl climbs on as did at the previous stop, whereas no boys get on or off. At the fourth stop, one girl leaves the bus, and the number of boys getting onto the bus means that, now, there are an equal number of girls and boys on the bus. Now the bus reaches its destination. From the information provided, how many children does the bus driver homeschool?
It all depends on who is reading this. If I'm the bus driver....than I homeschool two kids (even though I have 3 kids). Is that right?? I'm not very good with riddles. If I were to give my kid a riddle it would probably be: Which came first...the chicken or the egg? My brain can't seem to think much more beyond that. Sad, I know. :lol:
Yes, that's right. The point is that only the first and last sentences of the question are relevant - even though I'll guarantee that most students, when hearing the question (not reading it) will forget the part about them driving the bus. They will focus on the numbers and assume they are important - when they are not. That's true in life, right? It's important to see past the irrelevant stuff and focus on the real issues. Personally, I think lessons of this type - exemplified sometimes by 'trick' questions - are really valuable. It's selective attention, right? Have you ever watched this video?
