# Category Articles

Marcelino Menéndez Pelayo was a writer and great Spanish Spanish scholar, philologist, critic and historian. Scholar of ideas and a student of Hispanic Culture, he left us great works that reflected his great ideas and theories for a new awakening of the Hispanic world. Marcelino Menéndez Pelayo was able to recognize the role that Catholicism played for Spain, as José María Jover points out: The consideration of Catholicism as the axis and nerve of our national culture.

The silhouette of the girl in the image is turning clockwise, or the opposite? This optical illusion was created by Nobuyuki Kayahara. Solution According to how we look at the image we can see the girl spinning in both directions. Intuitively, most people see her initially turning left.
In this painting by Octavio Ocampo entitled The General's Family, we can see all the members of the family. Could you say how many people are in the box? Solution Up to 9 people can be counted in this painting:
Surely we have heard many times the expression "It doesn't matter eight times eighty." Let's prove it: Let's call x = 80-8 Squared: x 2 = 80 2 -2 · 80 · 8 + 8 2 Substituting x 2 = x (80-8) = 80x-8x is: 80x-8x = 80 2 -2 · 80 · 8 + 8 2 Reordering: 80 · 8-8 2 -8x = 80 2 -80 · 8-80x Factoring: 8 (80-8-x) = 80 (80-8-x) Y dividing a both sides of the equality between (80-8-x) we have to 8 = 80!
A sultan thought about increasing the number of women in his country so that men could have bigger harems. To achieve this, he formulated the following law: As soon as a mother gives birth to her first male child, she will be prohibited from having more children. In this way, the Sultan tried to ensure that there were no more than one male in the family offspring and instead the number of women was not limited.
John and Smith are playing the match game of which John is an expert player. The game consists of removing 40 matches from the table by taking turns 1, 3 or 5 matches in each turn. The one who removes the last group of matches is the winner. John, who does not like to lose, offers his friend an advantage and allows him to take the first turn in which Smith pulls 3 matches from the table.
Surely, you will have seen on some occasion how the modelers manage to build the model of a ship inside a bottle. Normally, the boat is built out of the bottle with the sails folded, then the model is introduced into the bottle through the hole and the sails and other accessories are deployed using tweezers until the model is completely assembled.
The image circuit uses only positive integers. When a number enters this circuit it is placed in the Entry box and following the arrows it advances until it reaches the Exit. In each box you must perform the operation indicated and continue your journey. If we arrive at the exit with the number 17.
Find a positive integer X less than 1000 such that the preceding number (X - 1) is a square, that is, it can be expressed as (X - 1) = Y 2 and the next number (X + 1) is a cube, that is to say that it can be expressed as (X + 1) = Z 3. Solution The only number that meets this property is 26.
The image shows two black horses and two white horses. The objective of the game is to exchange the horses with each other so that the white horses are on the right occupying the positions that initially occupy the black horses and vice versa. How many movements do you need?
If seven boys eat seven candies every seven days and nine girls eat nine candies every nine days, who eats more candies? Solution Each boy eats a candy every 7 days instead a girl takes 9 days to eat the same candy, so the boys eat more candy.
Two brothers have a flock of sheep. One day a buyer appears at home and makes the following offer: "I offer you as many euros per sheep as there are sheep in the flock." Seeing the amount of money he represented, the brothers accepted the deal without hesitation and the buyer paid them using 10-euro bills and some 1-euro coins.
"Good morning, officer," said Mr. McGuire. "Can you tell me what time it is'?" "I can do that exactly," replied Agent Clancy, who was known as the mathematical cop. "Add a quarter of the time between midnight and now at half the time between now and midnight and you will know the exact time."
What will be the maximum sum of points that can be obtained by simultaneously rolling four dice, taking into account that no number can be repeated? Solution 6 + 5 + 4 + 3 = 18
This problem was raised in a job interview at Google. We have 6 blue balls, 6 red balls and 2 opaque barrels in which it is not possible to see the content. All balls must be placed in the barrels and you ask a friend to take a ball out of a random barrel. What ball distribution maximizes the likelihood of your friend taking out a blue ball?
In one of the stages of the cycling lap the winner arrived at the scheduled time after taking an average of 30Km / h. The last cyclist with an average of 25Km / h arrived an hour later. What was the length of the stage? Solution The length was 150Km. For every 30 km, the winner of the stage took 1 hour while the loser needed 1.20 hours.
The average of the marks obtained in a class with 20 students has been 6. Eight students have suspended with a 3 and the rest have exceeded 5. What has been the average grade of the approved students? Solution If 8 students have scored a 3, to compensate for this grade in the total average, it means that 8 students have scored a 9.
Humberto gave 25 books to his son Ivan. On the other hand, Quique gave his son Erik 7 books. Between the two children they increased the amount of books they had in 25. How can you explain this phenomenon? Solution The characters are: a grandson (Erik), a son (Quique), his father (Iván) and grandfather (Humberto is Ivan's father and Quique's grandfather).
In a movie theater with capacity for 400 people, the latest film by a well-known Spanish director is released. Knowing that the occupancy of the room is 95%, what is the probability that two people will reach the same day? Solution If the room capacity is 400 people and is 95% complete, we have 380 people in the room.
The image shows an incomplete geomagical and magical square. In a similar way to the magic squares in which when adding all the numbers of a row, column or diagonal we always get the same result, in this geomagic square if we put all the pieces of a row, column or diagonal together we can always form a magic square of the same size with the numbers from 1 to 15 always placed in the same arrangement.
If it is blue, it is round. If it is square it is red. It is white or yellow. If it is yellow, it is square. It is square or round. What conclusion can we draw? Solution We know that it is white or yellow and that it is square or round. As we know that if it is square it is red and cannot be red, it must be round.