If a plane intersects all edges of a cone parallel to its bases, it divides the solid into two others: a new cone and a cone trunk. The trunk of the regular circular cone follows: the major and minor bases are parallel; The height of the trunk is given by the distance between the planes that contains the bases.
Starting from zero, add the odd sequence and the answer will be a perfect square. Ex: Starting from 0, we add the first positive odd number, 1. We find the perfect square 1. Now we add the next odd number, 3. And so on. 0 + 1 = 1 1+ 3 = 4 4 + 5 = 9 9 + 7 = 16 16 + 9 = 25 25 + 11 = 36 36 + 13 = 49… * Submitted by Jorge Pereira Junior Nine tables with fingers Index Next >> What are the leap years?
This is a simple way to multiply (from 1 to 10) by 9. We should consider the fingers counting from left to right and numbering them sequentially from 1 to 10. So, just lower the finger corresponding to the number we want to multiply by 9, and we will have the result. For example: 4x9.
A century begins in a year 01 and ends in a year 00. For example, the twentieth century began in 1901 and ended in 2000 and the 21st century began in 2001 and will end in 2100. However, for some, they recognize the changes made. To the Gregorian calendar in 1582, a century begins in a year 00 and ends in a year 99.
Take 5 coins and have one person arrange them the way they want (face or crown up). For example: See that in this example 3 crowns and 2 heads were chosen. Now turn around and ask the person to flip as many coins as he wants. Each time she turns a coin, she must say the word "I will come".
Fermat's highest known cousin record: 167176 32768 +1, which has 171153 digits was discovered by Yves Gallot (this is the eighth largest known cousin today, and the largest known non-mersenne cousin. What are friendly numbers? Index Next >> How many decimal places of the number Pi are known?
Do you know the origin of superstition around the number 13? In Norse mythology, we find a legend on the subject. Odin, chief of an Asian tribe, established his kingdom in Scandinavia. To administer it, celebrate religious rituals, and foretell the future, Odin would have chosen twelve sages, gathering them at a banquet at the Valhalla, abode of the gods.
The inch is an English unit of measure. It is equivalent to 2.54 centimeters or 25.4 mm. It originates in the ancient age, when the Romans measured the length with their own thumb. Thus, the inch is the width of a regular human thumb, measured at the base of the nail. In an adult human, this measurement is approximately 2.5 cm.
The numeric characters we use today have an Arabic (probably Moroccan) origin and are over a thousand years old. One possible historical explanation is that erosion from use has altered them slightly, but the original idea seems to have a curious explanation: "1" has an angle O "2" has two angles O "3" has three angles… The "0" has zero angles!
We currently define prime numbers as those that have only 4 divisors: + or - itself, +1 and -1. But when first thought out, most likely by Pythagoras, about 530 BC, the word prime was not related, but rather primary. The idea of primary numbers, introduced by Pythagoras, continues today.
According to data collected by IBGE, if Brazil were a country with 100 people, for each group of 100 people the country would have: - 18 functional illiterate people; - 16 rural workers; - 20 couples; - 51 women; - 50 people of class C; - 28 people with home phones; - 7 blacks; - 74 Catholics; - 10 graduates in any college; - 42 Southeast residents.
The word sine is derived from the Latin sinus meaning "bay" or "fold" from an erroneous (Arabic) translation of the Sanskrit jiva, and its variant jya. Aryabhata used the term ardha-jiva ("half-rope"), which was abbreviated to jiva and then transliterated by the Arabs as jiba. European translators such as Robert of Chester and Gherardo of Cremona in twelfth-century Toledo mistook jiba for jaib, meaning "bay," probably because jiba and jaib are written in the same way in Arabic script (this writing system in one of their form does not provide the reader with complete information about the vowels).
Here at the Hotel de Hilbert, there are always vacancies! In 1925 Hilbert presented an infinity paradox that became better known as the Hilbert Hotel. There are infinite guests in this hotel and it is packed, but whenever a customer arrives the manager asks guests to jump from room to room next door.
If we sleep an average of 8 hours a day, at age 40 we will have slept 13 years. The skeleton of a 64-pound man weighs about 11 pounds. One person blinks about 25,000 times a day. If heart disease, cancer, and diabetes were eradicated, a man's life expectancy would be 99.2 years.
The sign of X, which we indicate in the multiplication, was used by the English mathematician Guilherme Oughtred in the book Clavis Matematicae, published in 1631. That same year, Harriot, to also indicate the product to be made, placed a point between the factors. By 1637 Descartes was already limited to writing the juxtaposed factors, thus abbreviating any product.
Former shepherds, to control their flocks of sheep, associated them with stones that they kept in bags. Each sheep corresponded to a pebble. At the beginning and end of the day, they made the appropriate correspondences. If stone was left, sheep was missing. Since Latin in stone means "Calculus", hence the word calculus.
Lady's Age Difficulty Level: - I'm twice as old as you were when I was the age of four. In five years the sum of our ages will be 82 years. If you were one of those present, would you conclude that you are how old? Challenge 12 Escalator Challenge Index Next >> Challenge 14 Wine Bottles