In the history of mathematics, there is a problem of planting 20 trees, which has been famous all over the world for centuries, and has continuously nourished and enlightened human wisdom. 20 Trees Planting Question: If there are 20 trees, if there are four trees in each row, ask how to plant them to make more rows? To put it simply: there are 20 trees, if there are four trees in each row, ask how to plant them to make more rows?

20 trees planting problem, as early as the sixteenth century, ancient Greece, ancient Rome, ancient Egypt and other countries have completed the arrangement of 16 rows.

In the eighteenth century, the German mathematician Gauss conjectured that the problem of planting trees with 20 trees should reach 18 lines, but he has not been able to see the 18 lines of the map drawn by him. It was not until the nineteenth century that this conjecture was discovered by the American entertaining mathematician Sam Murphy. Lloyd completed and drew a beautiful eighteen-line diagram, which was later made into a recreational chess game that was popular in Europe and the United States, and was quite popular among people.

In the 20th century, the rapid development of electronic computers was in the ascendant. The mathematical problem of planting trees with 20 trees has also been updated. In the seventies of the twentieth century, two mathematics enthusiasts skillfully used electronic computers to surpass the mathematician Sam. Lloyd's eighteen lines of record have succeeded in drawing a beautiful twenty-line chart, setting a new record for 20 trees in the new century and standing it to this day.

The 20 trees planting problem is a mathematical problem, but if you know the answer, it is easy to draw a picture, unlike some world mathematical problems that require strong logical deduction ability. The answer to this math problem is very beautifully illprinted, and this problem can also be said to be an interesting problem.

Bai Ziyun came up with a math problem and used the number of true disciples as a temptation, in order to make the world pay attention to mathematics. Because mathematics is the foundation of all subjects. Mathematics plays an irreplaceable role in the historical development and social life of mankind, and is also an indispensable basic tool for learning and researching modern science and technology.

Mathematics is an abstract subject. And rigorous process is the key to mathematical abstraction. It takes a rigorous mind to study mathematics, but now this late Han Dynasty time and space. Bai Ziyun has continuously added modern knowledge achievements to this era, which has caused the scientific and technological seedlings of this time and space to grow.

Now there are many people in Zhuoxian County who have learned modern advanced mathematical knowledge, but they can only use it, and they don't know where this theorem or formula comes from. If this continues, there is no need to think about the emergence of mathematicians in this space-time.

In view of this, Bai Ziyun began to encourage everyone to open their minds. Unleash math puzzles to spark a math research boom. This is the case with the problem of planting 20 trees, of course, his status as a true disciple is not so easy to obtain, and there is a time limit for solving this problem, and it will be able to solve it within three months.

After the Green Devil Ape, Bai Ziyun began to build a mutant laboratory, which was quite large, extremely secretive, and very tightly defended, which could compete with modern military bases.

During this period. There have been several mutant disturbances one after another, but his ability is not as powerful as that of the Green Devil Ape, and he was easily subdued by the people of the Six Gates and the Demon Slaying Hall and pressed into the mutant laboratory. It became a test subject for the study of demons.

At the end of August, suddenly his subordinates reported that 10,000 imperial Red Armor troops had entered the territory of Zhuo County. is running to Zhuo County.

"The Red Armor?" Bai Ziyun suddenly smiled, "It's the Red Immortal Army, the new army made by the emperor." Aren't they going into the desert to kill the Xianbei Hulu? What are you doing in Zhuo County? Mao Zong, you talk about it. Why did 10,000 Red Armor troops come to Zhuo County? ”

Mao Zong frowned and thought for a while, then hesitated: "They won't come to attack us, right?" ”

Bai Ziyun rolled his eyes, most of this kid's mind was on Gewu, and he basically didn't care about analyzing the situation and the military, so he said angrily: "Doesn't the Red Immortal Army have 30,000 horses?" The imperial court is confident that 10,000 horses will take our Zhuo County? ”

"Ah, yes." Mao Zong reacted at this time and asked, "Master, what are they doing here?" ”

Bai Ziyun said with a smile: "It should be from the convergence with Xia Yu, the captain of Wuhuan." But he didn't wait in Shanggu County, but came to Zhuo County, obviously to provoke, if he didn't give them some color, he would be despised by them, and he would pass the order down, and let Bai Ma Yicong drive this group of people out of Zhuo County. ”

At this time, Mao Zong also shook his head and said: "The leader of this group of centaurs is brainless enough, since he is not here to fight, but he has nothing to do, and he is here to play provocation, isn't this looking for a draw?" ”

He is not worried at all that Bai Ma Yicong will not be able to defeat the 10,000 Red Immortal Army, in the past year, the Dragon Elephant Army and Bai Ma Yicong have worked hard every day, with sufficient food and grass, assisted by medicine, especially to improve the small return pill every day, so that the cultivation of the soldiers of the two armies has grown rapidly, and thirty percent of the soldiers have entered the fourth layer of the Dragon Elephant Prajna Gong, that is, the second-rate realm. The more the Dragon Elephant Praruo Gong is cultivated, the more difficult it will be, Mao Zong does not believe that without the assistance of medicine, the people of the Red Immortal Army can enter the fourth layer within a year or two, unless there is Zhang Fei's talent is still about the same.

Thinking of Zhang Fei, Zhang Fei's loud voice came.

"Master, I heard that there is going to be a war, can I also put on armor and kill the enemy?"

While speaking, Zhang Fei's burly and sturdy figure appeared in the room, Zhang Fei is only twelve years old this year, but because of his talent and cultivation of dragon elephant skills, his figure is already about the same as that of an adult, and his muscles are knotted, containing terrifying explosive power.

Bai Ziyun frowned and reprimanded: "Ah Fei, you have been learning etiquette with Young Master Lu for more than a year, why are you still so arrogant, you don't say please when you enter the door, you will come first before you arrive, such an impatient character, how can you rely on you as a teacher?" ”

Zhang Fei was reprimanded, his neck immediately shrank, and he said with a sneer: "What the master blames is that the disciple is full of joy when he hears that there is a battle to fight, and he forgets the etiquette for a while, and hopes that the master will forgive his sins." He bowed and bowed, and looked humble.

"Hmm." Bai Ziyun saw that he was saluting, nodded with satisfaction, looked at him for a while, and said, "I heard that you exchanged the lion's roar in the Tibetan Scripture Pavilion, how are you cultivating now?" ”

Zhang Fei raised his eyebrows proudly and said: "This exercise, I started in one day, but in a month, I practiced to the fullest, I heard that other people who practice this exercise, more than a month have not started, master, you see, the disciple's martial arts training qualifications are amazing." ”

At this time, Mao Zong interjected and smiled: "It's not that your qualifications are good, but that this kind of exercise is just very suitable for your talent, martial arts cultivation depends on whether it is suitable or not, you go to practice the embroidery needle of the Sunflower Treasure Book to try, and you are guaranteed to practice it for the rest of your life." ”

Zhang Fei's eyes widened, and he shouted loudly: "What martial arts I can't learn?" I don't believe that I can't learn the embroidery needle of the Sunflower Treasure Book, hum, Mao Zong, you dare to look down on me, I will go to the Tibetan Scripture Pavilion to exchange this martial art later. He was in a hurry, and opened his mouth to say again.

"Haha!" Mao Zong hugged his stomach and laughed, tears of laughter flowed out, and he pointed at Zhang Fei and said with a smile: "Ah Fei, don't you know that the cultivation of the Sunflower Treasure Book is from the palace?" You went to practice the embroidery needle of the Sunflower Treasure Book, don't you want to fulfill your filial piety? ”

"Okay, you kid dare to entertain me."

Zhang Fei only reacted at this time, his face was red and his ears were red, and he came to Mao Zong's side in a few steps, and grabbed Mao Zong, Mao Zong's feet moved, and one side of his body avoided it, Zhang Fei's eyes widened, and he stretched out his claws to grab it, and the two of them immediately fisted and kicked each other, playing in the hall.

Bai Ziyun was also a waner, smiling at the banter of the two disciples.

After a while, the fight between the two became faster and faster, and with the whirring wind, the fight seemed to become more intense. Bai Ziyun couldn't help frowning.

At this time, Mao Zong jumped away, waved his hand and said, "Don't fight, don't fight, your guy has so much strength that it makes my arm hurt." ”

"Humph!" Zhang Fei still exhaled angrily: "You guy is really boring, he ran away after a few hits, it's not fun at all." ”

"I'm not majoring in martial arts, so naturally I can't compare with you, a martial artist." Mao Zong squinted and smiled, "If you want to fight, you can go to the Red Immortal Army of the imperial court, let them know how powerful you are, and make a name for yourself." ”

"Okay, that's what I mean." Zhang Fei looked at Bai Ziyun and said solemnly: "Master, disciple, please fight!" ”

Bai Ziyun shook his head and said: "You are only twelve years old this year, killing people and seeing blood is too cruel after all, you are still young and have poor ability to bear it, let's wait a few years." ”

Don't look at Zhang Fei's height and horse, but his age is only twelve years old after all, he is still a boy by current standards, and he will kill people at such a young age, Bai Ziyun is worried that he will leave a shadow in his heart, after all, children's psychology is generally fragile, and the battlefield is too bloody and cruel, it would be bad if he had a shadow on his psychology.

Zhang Fei looked at Bai Ziyun with a blank eye, and begged: "You just let me go, can those Red Immortal Army eggs still hurt me?" ”

"Master is not worried that the Red Immortal Army will hurt you, you have now reached the sixth layer of the Dragon Elephant Prajna Gong, and your strength is infinite, and you can completely fight against the masters of the first-class realm. As a teacher, the heart is that you are too killing, which will cause demonic obstacles in your soul, which will not be conducive to your future cultivation. ”

Zhang Fei suddenly pursed his lips, and secretly glanced at Mao Zong, and Mao Zong said: "Master, Ah Fei's ambition is to be a general who goes on a horse to kill the enemy, and it is inevitable to fight bloody battles in the future. After all, the 10,000 Red Immortal Army is a soldier and horse of the imperial court, and we are not suitable for killing too much, didn't Ah Fei recently practice the lion's roar? Wouldn't it be better to let him yell a few times in front of the army to deter the Red Immortal Army and let them retreat in the face of difficulties? ”

Bai Ziyun was slightly stunned, then nodded and said, "Okay, that's it." (To be continued......)

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