Ask your friends if they are able to write 5 odd numbers that add up to fourteen. It is amazing how many people are abstracted and absorbed, and the amount of time they spend on this problem with the naked eye so simple. Remember that we talk about numbers, not numbers. Solution Here's the solution: 11 + 1 + 1 + 1 = 14.
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In each of the four corners of a square room sits a cat. Three cats sit in front of each cat. A cat sits on each tail. How many cats are in total in the room? Solution If we respond quickly it is possible that we have counted 32 cats: 4 cats in the corners, in front of each other three other cats, which are 12 cats and also in the tail of each cat another cat or 16 cats.
In a televised contest two teams compete by performing different tests. The winner of each test receives a fixed amount of points (the same in all tests) and the loser receives a fixed amount of points less than that of the winner. After several tests, one team has 231 points and another, which won exactly 3 tests, has 176 points.
Three thieves from the Ali Baba band found a treasure that contained a large amount of gold coins and jewels and decided to distribute it equally among the three without reporting the discovery to the head of the band. The problem was that they could not agree with the cast, since everyone had different opinions when assessing the pieces found.
We have six glasses in a row as seen in the first image. Three are full of water and three empty. Moving a single glass, how can we make the full and empty glasses alternate as shown in the second image? Solution Take the second glass and pour the contents onto the one in fifth position.
The magic square of Alberto Durero, carved in his work Melancolía I is considered the first of the European arts. In the square of order four the magic constant 34 is obtained in rows, columns, main diagonals, in the four sub-matrices of order 2 into which the square can be divided, adding the numbers of the corners and also adding the four central numbers.
We will call all that prime number binary cousin such that, expressed in base 10, it is written only with the digits 0 and 1. The first one that only needs the digit 1 to be written is 11. What is the next "Binary cousin" whose digits are all 1? Extracted from the page http: // www.
Two hours ago it had been as long as one o'clock in the afternoon as it was until one o'clock in the morning. What time is now? Solution It's nine o'clock. Since there are 12 hours between one in the afternoon and one in the morning and half that time is six hours, it was 6 + 1 = seven two hours ago and therefore it is now nine.
When I turned fifty my first grandson was born. Now that I am on my way to seventy, I have many more: "Each of my children has as many children as brothers and the combined number of my children and grandchildren is exactly my age." How old am I? Solution There are several ways to solve this problem.
The recent news that someone had won 777,777 francs in a Monte Carlo casino reminds me of the principle of the Lord Rosslyn game system widespread a few years ago. Without going into the technical issues of roulette as practiced in Monte Carlo, we know that Lord Rosslyn's system was based on the principle of betting on multiples of seven and we will ask our readers to solve the following problem.
We have a bag that contains a total of 71 delicious candies of different flavors. There are twice as many lemon candies as strawberry candies, orange candies are one less than strawberry candies and mint candies are six candies less than lemon candies. How many delicious candies will you have to extract at least from the bag (without looking) to be sure you can eat two different flavors?
A train that is 500 meters long travels at half a kilometer per minute and goes through a tunnel 500 meters long. How long will it take to completely cross the tunnel? Solution Its speed is half a kilometer per minute = 500m per minute. The first minute enters whole and the second minute leaves whole or another explanation the 500m train plus the 500m tunnel gives a kilometer that the train has to travel if it goes to 500m per minute it will take two minutes to finish.
The other day my math teacher wrote a four-digit number on the board, took the eraser and said I was able to divide it by five simply by erasing the thousands digit. Indeed, after deleting that digit the number was divided by five. And there is more, he said, I will divide it again by five by deleting the digit of hundreds.
We have a series of circles linked by lines that form squares and triangles. In each circle we must place a number from 1 to 9 without repeating any so that the sum of the values of the circles coincides with the value shown in the triangle or square they form. You will find many examples on the page of Guillermo Verger.
We will call tricubic numbers to those in which the sum of the power of 3 of each of the digits that compose it is equal to the number itself, such as: What is the next tricubic number? Extracted from the page http://www.acertijosypasatiempos.com Solution The following is:
The attached illustration shows an operator raising the combat flags that, for the benefit of all those unfamiliar with naval signals, we will explain that they represent the famous battle cry of the Spanish-American war: “Remember the Maine !. The commander is shown preparing on the map the plan of attack with which he intends to attack and sink the entire fleet of enemy ships, destroying them as quickly as possible.
In a group of 230 students of a school there are: 15 who practice football, athletics and basketball. 23 who practice soccer and basketball. 36 who practice athletics and basketball. 28 who practice athletics and soccer. 61 who practice football. 64 who practice basketball. 75 who practice athletics. How many students do not practice any sport?
At the end of the last meeting of my company there were 15 handshakes among all attendees. How many were at the meeting? Solution We were 6 people. If each person greeted each of the others there would be 6 * 5 = 30 greetings but since each hand shake is shared by two people we have to divide this amount by two.
At snack time, it turns out that we have a plate with 5 equal donuts and we are 6 friends. One of the boys proposes to divide the 5 donuts into 6 equal pieces each so that we will have 5 equal pieces for each and we will all eat the same. However, another of the boys, very fond of ingenuity games, challenged us to see if we were able to divide each donut in equal parts but without cutting any donut into six or more pieces so that we all have the same amount.
On August 25, 2001 Juan turned as many years as the result of adding the digits of the year of his birth. In what year was Juan born? Solution We can say that Juan was born in the year 19x and since being born in 2000 in 2001 he could not turn 2 + 0 + 0 + 0 = 2 years. Therefore, according to the statement, we have that the age at 2001 will be 10 + x + y We match both expressions and we have to: 2001 - 19xy = 10 + x + y; 1991 = 19xy + x + y 1900 + 91 = 1900 + 10x + y + x + y; 11x + 2y = 91 Equality is met for x = 7 and y = 7 So Juan was born on August 25, 1977.
We have two identical coins on one table next to each other. If we turn the coin on the left, without lifting it from the table, rolling it over the edge of the coin on the right until it is placed in the area marked in red, how will the coin be oriented? Will the 1 remain straight or the other way around? Solution Although intuitively it seems that the coin should turn around as we rotate it over half the circumference of the other coin, it will actually take a full turn so that it will be in the same orientation as at the beginning, with the 1 to the right .