* Why is a manhole cover round? 为什么下水道的井盖是圆的? * How many cars are there in the 美国有多少辆车? * You‘ve got someone working for you for seven days and a gold bar to pay them. The gold bar is segmented into seven connected pieces. You must give them a piece of gold at the end of every day. If you are only allowed to make two breaks in the gold bar, how do you pay your worker? 你让某些人为你工作了七天,你要用一根金条作为报酬。这根金条要被分成七块。你必须在每天的活干完后交给他们一块。如果你只能将这根金条切割两次,你怎样给这些工人分? * One train leaves 一列火车以每小时15英里的速度离开洛杉矶,朝纽约进发。另外一列火车以每小时20英里的速度离开纽约,朝洛杉矶进发。如果一只每小时飞行 * You have two jars, 50 red marbles and 50 blue marbles. A jar will be picked at random, and then a marble will be picked from the jar. Placing all of the marbles in the jars, how can you maximize the chances of a red marble being picked? What are the exact odds of getting a red marble using your scheme? 你有两个罐子,分别装着50个红色的玻璃球和50个蓝色的玻璃球。随意拿起一个罐子,然后从里面拿出一个玻璃球。怎样最大程度地增加让自己拿到红球的机会?利用这种方法,拿到红球的几率有多大? * Imagine you are standing in front of a mirror, facing it. Raise your left hand. Raise your right hand. Look at your reflection. When you raise your left hand your reflection raises what appears to be his right hand. But when you tilt your head up, your reflection does too, and does not appear to tilt his/her head down. Why is it that the mirror appears to reverse left and right, but not up and down? 假设你站在镜子前,抬起左手,抬起右手,看看镜中的自己。当你抬起左手时,镜中的自己抬起的似乎是右手。可是当你仰头时,镜中的自己也在仰头,而不是低头。为什么镜子中的影像似乎颠倒了左右,却没有颠倒上下? * You have 4 jars of pills. Each pill is a certain weight, except for contaminated pills contained in one jar, where each pill is weight + 1. How could you tell which jar had the contaminated pills in just one measurement? 你有4瓶药。每粒药丸的重量是固定的,不过其中有一瓶药受到了污染,药丸的重量发生了变化,每个药丸增加了一点重量。你怎样一下子测出哪瓶药是遭到污染的呢? * If you had an infinite supply of water and a 5 quart and 3 quart pail, how would you measure exactly 4 quarts? 如果你有一个 * You have a bucket of jelly beans. Some are red, some are blue, and some green. With your eyes closed, pick out 2 of a like color. How many do you have to grab to be sure you have 2 of the same? 你有一袋糖,有红色的,蓝色的,绿色的。闭上眼睛,拿出两块颜色一样的糖,你需要拿多少次才能确保有两块颜色相同的? 答案: ★为什么下水道的井盖是圆的? ★美国有多少辆车?(一个常见的类似问题是:美国有多少家加油站?) |
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