1, there are two uneven distributions, the time is over, what is the method you can use to determine a 15 minute time?
2, a manager has three daughters, the age of the three daughters is equal to 13, and the age of three daughters takes the age of the manager's own age, there is a subsidiary of the manager's age, but still can't determine the age of three daughters of the manager. At this time, the manager said that only a daughter's hair is black, then this subordinates know the age of three daughters. What is the age of three daughters? why?
3, there are three people to go to the hotel, stay in three rooms, each room is $ 10, so they pay for the boss $ 30, the second day, the boss thinks that only $ 25 is only $ 25 yuan, I'm going to return to the younger brother to return $ 5 Three guests, who knows that the younger brother is greedy, only returning each person $ 1, secretly takes $ 2, so that the three guests have spent 9 yuan, so three people spent $ 27, plus the younger Over $ 2, a total of $ 29. However, when they had a total of $ 30, there were $ 1?
4, there are two blind people, they all bought two pairs of black socks and two pairs of white socks, eight pairs of socks, the size is exactly the same, and each pair of socks have a trademark paper. Two blind people accidentally mixed eight pairs of socks. How do each person retrieve the black socks and white socks?
5. There is a train to leave Los Angeles straight to New York at a speed of 15 kilometers per hour, and another train takes 20 km per hour from New York to Los Angeles. If there is a bird, start at the same time and two trains at the same time, from Los Angeles, return to another car, return to the two trains, until the two trains meet, this is only How long is the bird fly?
6, you have two jars, 50 red playball, 50 blue playball, randomly select a jar, randomly select a playball to put the jar, how to give red play the biggest choice? In your plan, what is the accurate chance of the red ball?
7, you have four pot pills, each pill has a certain weight, the contaminated pill is not polluted by weight 1. Only weigh once, how to determine which can the medicine is contaminated? 8, you have a bucket of jelly, including yellow, green, red, close your eyes, and grab the jelly of two homing colors. How many can you determine if you have two simultaneous jelly?
9. A number of lights numbered 1 to 100, all the switches facing up (open) * do: Any 1 multiplier dialed switch; 2 multiples reverse the direction of the switch; 3 multiples against the direction I all dial a switch ... Q: The last is the number of the lamp that is turned off. 10, imagine that you are in the mirror, please ask, why do images in the mirror can be reversed, but can't you reverse it?
11, a group of people dance, every person wear a hat. There are only two black and white in the hat, and there is at least one black. Everyone can see the color of other people's hats, but they can't see themselves. The moderator first let everyone see what the hat is wearing it, then turn off the lights. If someone thinks it is a black hat, I will play myself a slap. The first time turns the light, no sound. So I opened the lights, everyone will look at it again, and still sword when they turn off the lights. Or until the third turn, there was a sound of the slap in the light. How many people wear a black hat?
See how you can do it?
