# Category Information

Study on the impact of meditation on the brain Recently Harvard researchers have shown that practicing meditation regularly thickens the cerebral cortex. Apparently our cerebral cortex thins as we age, but in people who meditate regularly, their gray matter tends to have the opposite effect, that is, it tends to thicken.

Today the shadow of a plane that was about to land has passed over me. Coincidentally, later I took that same plane and I could see its shadow at high altitude. Which one was older? , The shadow of the plane near the ground or the shadow of the plane at high altitude? Solution Both will be approximately the same size.
Anyone with average culinary skills can take a few eggs and make an omelet with them. The opposite, of course, is more difficult. How much would a device that produce whole eggs produce from tortillas? Even with an unlimited budget, the brightest engineers probably wouldn't.
In the last elections of a small town on the coast there were 5,219 votes and four candidates. It is known that the winner of the elections exceeded his opponents by 22, 30 and 73 votes although due to a computer problem, information regarding the exact number of votes that each candidate obtained was lost.
The caterpillar thinks that both she and the lizard are crazy. If what the sane believes is always true and what the madman believes is always false, is the lizard sane or crazy? Solution The caterpillar cannot be sane because it thinks it is crazy and the ropes do not lie. Therefore she is crazy and if the lizard were too, the caterpillar would think what is true, which contradicts the definition of madmen who always believe what is false.
There is a curious mathematical operation called Kaprekar Operation that is somewhat unique. It consists in rearranging the digits of a number so that the largest and smallest possible number is obtained, then subtracting the smallest from the largest. This operation can be applied to numbers of any size and can be repeated over and over again on the result obtained.
The implicit faith that the ancient Greeks, Romans and Egyptians deposited in the oracles of their gods can be appreciated when we warn that from the declaration of a war to the sale of a cow, no transaction was carried out without the advice and approval of the oracles Jupiter's famous painting in Dodona shows two peasants consulting the oracle about some minor matter and they are ordered to look in a mirror.
We have three children and we show them three red and two green hats. We put them in a row and put each one a hat on their head, so that the first one cannot see any hat, the second one sees one and the third one two, then we tell them that the first one to guess what color their hat is , you will have a bag of prize treats.
Fill in the following table with 4 digits from 1 to 9 so that the numbers that form comply with the following: The number formed by the two digits of row 1 is a multiple of 5 and 3. The number formed by the two digits of row 2 is a multiple of 9. The number formed by the two digits of column A (read from top to bottom) is a multiple of 4.
In three farms there are a total of 333 animals. In the first farm there are triple the number of animals than in the second and in the second, twice as much as in the third. How many animals will have to be passed from the first farm to the others so that the number of animals in each one is a different three-figure number?
All patients who go to the aesthetic clinic are subjected to a rigorous control in which they are weighed. In one week the average weight of the men who attended the consultation has been 90 Kg., While the average weight of women has been 65 Kg. If we average all weights counting men and women we gives 75 kg
In a single game against married, Juan is looking at Carmen and Carmen is looking at David. Juan is married and David is single. Is there a married man looking at a single person? a) Yes b) No c) It cannot be determined safely Solution Since you can only be married or single we have 2 possibilities for Carmen: option 1 -> Carmen is single.
A grandfather went to pick mushrooms in the forest with his four grandchildren. In the forest they dispersed and began searching. After a while the grandfather had 45 mushrooms and none of his grandchildren had managed to find even one. The grandfather distributed all his mushrooms among the grandchildren who again looked for while the grandfather took a nap under a tree.
In a small village hidden among the mountains, 2/3 of the men are married to 3/5 of the women. The tradition of this people stipulates that they should never marry outsiders. What is the proportion of single people? Solution 7/19
Ashraf and Ali were two Egyptian camel drivers from Sharkieh province. One day they decided to change jobs and work on grazing so they moved to Birqahs camel market to sell their animals. They sold each animal for an amount of pounds equal to the number of camels they sold.
The objective of the game is to join each pair of equal letters using horizontal or vertical lines so that all the squares of the board are occupied as in the example on the right. Also, the lines cannot cross. Solution The following image shows the solution:
There is a birthday party with 6 invited children. At the party a piñata is prepared with 21 goodies inside. When they break the piñata, the children run to collect their goodies. In the end each one gets a different number of goodies. How many goodies has each child got? Solution The first child has got 1 candy, the second 2, the third 3, the fourth 4, the fifth 5 and the sixth 6, or 21 in total.
Alberto is learning to write the numbers at school. Today the teacher has made them write all the numbers from one to 100. Do you know how many times she will have written the digit 3? Solution In total, you will have written the number 3 times. Once for every ten except 2 times for 33: 3, 13, 23, 33, etc.
It is really interesting that the split between 1 998 001 the result are a lengthy sequence of decimal perfectly ordered starting with 000, 001, 002, 003 ... and ends at 999 then repeated: 1/998001 = 0.000001002003004005006007008009010011012013014015016017018019020 0210220230240250260270280290300310320330340350360370380390400410420430440450 4604704804905005105205305405505605705805906006106206306406506606706806907007 1072073074075076077078079080081082083084085086087088089090091092093094095096 0970980991001011021031041051061071081091101111121131141151161171181191201211 2212312412512612712812913013113213313413513613713813914014114214314414514614 7148149150151152153154155156157158159160161162163164165166167168169170171172 1731741751761771781791801811821831841851861871881891901911921931941951961971 9819920020120220320420520620720820921021121221321421521621721821922022122222 32242252242242242242242242242242242242242242242242242242242242242242322242242242242242242242322242242322242242322242242242242242322242322242322242322242322242322242322242322242322242322242322242322242322242322242322242322125 532542552562572582592602612622632642652662672682692702712722732 7427527627727827928028128228328428528628728828929029129229329429529629729829 9300301302303304305306307308309310311312313314315316317318319320321322323324 3253263273283293303313323333343353363373383393403413423433443453463473483493 5035135235335435535635735835936036136236336436536636736836937037137237337437 5376377378379380381382383384385386387388389390391392393394395396397398399400 4014024034044054064074084094104114124134144154164174184194204214224234244254 2642742842943043143243343443543643743843944044144244344444544644744844945045 1452453454455456457458459460461462463464465466467468469470471472473474475476 4774784794804814824834844854864874884894904914924934944954964974984995005015 0250350450550650750850951051151251351451551651751851952052152252352452552652 7528529530531532533534535536537538539540541542543544545546547548549550551552 5535545555565575585595605615625635645655665675685695705715725735745755765775 785795805815 8258358458558658758858959059159259359459559659759859960060160260 3604605606607608609610611612613614615616617618619620621622623624625626627628 6296306316326336346356366376386396406416426436446456466476486496506516526536 5465565665765865966066166266366466566666766866967067167267367467567667767867 9680681682683684685686687688689690691692693694695696697698699700701702703704 7057067077087097107117127137147157167177187197207217227237247257267277287297 3073173273373473573673773873974074174274374474574674774874975075175275375475 5756757758759760761762763764765766767768769770771772773774775776777778779780 7817827837847857867877887897907917927937947957967977987998008018028038048058 0680780880981081181281381481581681781881982082182282382482582682782882983083 1832833834835836837838839840841842843844845846847848849850851852853854855856 8578588598608618628638648658668678688698708718728738748758768778788798808818 8288388488588688788888989089189289389489589689789889990090190290390490590690 79089099109 11912913914915916917918919920921922923924925926927928929930931932 9339349359369379389399409419429439449459469479489499509519529539549559569579 5895996096196296396496596696796896997097197297397497597697797897998098198298 3984985986987988989990991992993994995996997999 ... left as an exercise for the reader checking the validity of the division :).
Enrique has bought some sunglasses. If you put them indoors, you need to light two lamps to see as clearly as you do without your glasses on and with a single lamp. How many lamps do you need to turn on to look at your eyes in the mirror with your glasses on if you want to see them as clearly as you would see them without glasses and with a single lamp?
Every year in my neighborhood we organize a basketball competition called “8 hours of basketball”. In order to have as many participants as possible, we reduce the games to 20 minutes in time (without stopping the clock), plus 10 minutes of preparation between matches. Our competition model consists of games by lottery (looking for rest, if possible, the ones that have more matches at that time and that meetings between the same teams are not repeated as much as possible).