Classic 11 smart questions

1. There are two unevenly distributed fragrances. The burning time is one hour. How can you determine a period of 15 minutes?

2. A manager has three daughters. The three daughters are 13 years old, and the three daughters are equal to the manager's age. One subordinate has an known manager's age, however, I still cannot determine the age of the three daughters of the manager. The manager said that only one daughter had a black hair, and the subordinate knew the age of the three daughters of the manager. What is the age of the three daughters? Why?

3. Three people went to the hotel and stayed in three rooms. Each room was $10 yuan, so they paid the boss $30 in total. The next day, the boss thinks that only $25 is required for the three rooms, so he asks the younger brother to return $5 to the three guests. Who knows the younger brother is greedy and only returns $1 to each user, who secretly takes $2, in this way, nine yuan is spent for each of the three guests, so $27 is spent for each of the three guests. In addition, the younger brother swallowed up $2 for a total of $29. But when the three of them paid a total of $30, what about $1?

4. Two blind people bought two black so and two white so. The eight so have the same cloth quality and size, and each so has a trademark paper attached. The two blind people accidentally mixed up the eight-to-eight so. How can they retrieve black and white so pairs?

5. One train leaves Los Angeles at a rate of 15 kilometers per hour and goes straight to New York. The other train departs from New York to Los Angeles at a rate of 20 kilometers per hour. If a bird starts at a speed of 30 kilometers per hour and two trains start at the same time, it departs from Los Angeles and returns when it encounters another car. In turn, the two trains fly back and forth, it wasn't until two trains met. How long did the bird fly?

6. You have two cans, 50 red balls and 50 blue balls. You can select a random jar and place a ball in the jar. How can you give the biggest chance to select a red ball? In your plan, what is the exact chance of getting a red ball?

7. You have four cans containing pills. Each pill has a certain weight. The contaminated pills are not contaminated. + 1. how can I determine which jar of medicine is contaminated once?

8. You have a bucket of jelly, including yellow, green, and Red. Close your eyes and capture the jelly in the same color. You can determine if you have two joos of the same color after capturing them?

9. For a batch numbered 1 ~ 100, all turn (on) the light for the following *: All the multiples of 1 reverse direction dial one switch; 2 multiple reverse direction dial another switch; turn another switch in the opposite direction in multiples of 3 ...... Q: It is the number of the light that is turned off.

10. Imagine that you are in front of the mirror. Why can't images in the mirror be upside down, but not upside down?

11. A group of people wear a hat on their heads. There are only black and white hats, and at least one black hat. Everyone can see the colors of others' hats, but not their own. The host will show you what hats others wear on their heads and turn off the lights. If someone thinks they are wearing black hats, they will slap themselves in the face. Turn off the light for the first time and there is no sound. Then we turned on the light and watched it again. When the light was turned off, it was still silent. It was not until the third time that the light was turned off that there was a slap in the face. How many people are wearing black hats?