Datang: The prince of salted fish was overheard by Li Er

Wang Xiaotong understood the reason why Li You laughed.

Because this question also comes from "Sun Tzu's Mathematical Classics".

Just now Li You was able to solve the first problem, so naturally he can solve this one too.

Recently, Wang Xiaotong has been re-studying "Sun Tzu's Mathematical Classics", and he said it out of emotion just now.

Li You asked kindly: "Dr. Wang, do you need to change this question?"

Wang Xiaotong shook his head and said, "Since it has already been said, there is no need to change it."

"As I said just now, the solution to the problem is not the result, but the process. The king of Chu can just tell you how to solve the problem easily."

Li You didn't refuse, and immediately opened his mouth to answer.

"Okay then, this question comes from "Sun Tzu's Mathematical Classics", and the answer is 23."

"As for the process, it's actually very simple. The mathematical process is the optimal solution."

"It's just that the king has a poem, which is easier to remember and answer similar questions."

"The three of them walked together for seventy years, and there were twenty-one plum blossoms from five trees. The seven sons were reunited in half a month, and we will know when we divide one hundred and five."

As soon as Li You's formula came out, Li Anren quickly verified it.

In the first sentence, three people walk together for seventy times, which corresponds to the remaining two of the number three and three, that is, multiplying two times seventy equals 140.

Then twenty-one plum blossoms from five trees correspond to the remaining three of the five-five number, which is 63.

In the third sentence, the reunion of the seven sons is half a month, and there are 30 days in a month, and half a month is [-] days, which corresponds to the remaining two of the number of seven and seven, and the calculation result is thirty.

In the last sentence, divide by one hundred and five and you will know, first add up the above numbers to equal 230 three.

Then subtract two hundred and five to get 23.

"It really is!"

Li Anren found out in astonishment.

Then he experimented with several other "things don't know how many" questions, which can also be answered with Li You's formula.

"Forget it, King Chu's understanding of Sutra is already higher than this old man's!"

Wang Xiaotong said with emotion.

He naturally knew the contents of the sutra, but he couldn't convert it into a formula like Li You himself.

"King Chu Gaoming, I don't think there is any need to continue this competition."

By this time, Wang Xiaotong had completely given up.

However, although Wang Xiaotong gave up, Li Anren on the side hadn't given up yet.

"Teacher, let's listen to King Chu's topic first."

"Although the king of Chu knows the sutras well, we are not bad."

From Li Anren's stubborn face, Wang Xiaotong saw a little bit of his youthful appearance, and he was also greatly encouraged.

He cheered up again, looked at Li You and said, "King Chu, please come up with a question."

Li You had noticed the performance of Wang Xiaotong and Li Anren just now, compared to Wang Xiaotong, he is now more interested in Li Anren.

He raised his head to look at Li Anren and said, "Listen to the second question."

"Let's continue with the question just now. It's still the same river and the same fisherman."

"Fishermen have to deliver things from the downstream pier to the upstream pier every day, and then row back."

"This time, the king will not set any inducement conditions, so I will ask you if the speed of the water has any effect on the time for the boatman to go back and forth?"

As soon as Li You said this, Li Anren immediately laughed too.

"King Chu, you also said that you didn't set a trap."

"Isn't this question the same as the previous one? The current of water will not affect the fisherman's speed at all."

"In a downstream situation, the current speeds up the rowing speed, and in the upstream situation, the speed of the rowing boat will be correspondingly slowed down."

After finishing speaking, Li Anren even glanced proudly at his teacher Wang Xiaotong.

It seems to be saying, "Look, this king of Chu only has this little thing, the teacher just underestimated himself too much."

However, not long after Li Anren was complacent, Li You said with doubts: "Anren's words seem to have some truth."

"But if the speed of the water is too fast, when the speed of the water is equal to the speed of the boat, it seems that the fisherman can't sail against the current at all?"

Faced with this question from Li You, Li Anren was stunned.

He opened his mouth, but made no sound.

Li Anren felt that there was nothing wrong with his logic, but when Li You's situation was raised, he really couldn't justify himself.

Li You smiled slightly and said: "The first question just now, the hat and the fisherman's boat are in the river, and all the influence of the river water can be regarded as nothing."

"But in this question, although you have considered that the speed of increase and decrease of the water flow is the same when it is upstream and downstream, you have not considered that the locations of these two piers will not change due to the current."

"In fact, the faster the water flow, the faster it will go downstream, but it will take more time to go upstream. The two are not changing year-on-year."

"About this, you will find out later by taking out the paper and pen and bringing in the fixed numbers to calculate."

"Okay, isn't our competition over?"

Faced with Li You's kindness, Li Anren became stubborn again.

"It was agreed that there are three questions. Now the King of Chu is only one question ahead, and we still have a chance."

"King Chu, you won't force yourself to win."

Li You was helpless, he knew that in the face of such a person who was not willing to give up until the Yellow River, there was no way to convince him without thoroughly defeating him.

"Okay, then please come up with the third question."

Li Anren glanced at Wang Xiaotong.

Wang Xiao said, "An Ren, since you are unwilling, then this last question is up to you."

Li Anren nodded solemnly, then took out a pen and paper, and began to write and draw on it.

Soon Li Anren brought the topic in front of Li You.

"Prince Chu, this question is a bit complicated, and I can't do it mentally. Please help me with the calculation process."

Li You took the topic and looked at it, and shouted in his heart, good guy, it's just in time.

This is a question of volume: now there are 120 dendrobiums, seven buckets and three liters of millet, and a square warehouse and a circular warehouse should be built to store them.

The requirement is to fill the two warehouses with the same height.

At the same time, it is also required that the aspect is less than nine inches in diameter and more than two feet nine feet and eight inches in height, with a diameter of seven and a circumference of 22.

Finally, what are the square, diameter, and depth of these two warehouses?

After reading it, Li You looked up at Li Anren, then at Wang Xiaotong.

This kind of problem is exactly what Wang Xiaotong is best at.

There are many such questions in his book "Ji Gu Suan Jing".

"Ji Gu Suan Jing" involves a lot of three-dimensional volume calculations, Pythagorean calculations, establishment and solution of cubic equations, which are the most complicated mathematical problems in this era.

It is also the achievement Wang Xiaotong is most proud of.

And Li Anren finally asked such a question because he wanted to justify Wang Xiaotong's name.

At the same time, this is also a topic that is closely related to daily life.

He also followed this question to prove to his grandfather the application of arithmetic in civil engineering and water conservancy projects such as building dams, digging ditches, and building warehouses and cellars.

After being proficient in mathematics, these projects will get rid of the shortcomings of relying solely on experience in the past, making these projects more traceable.

Faced with such a problem, even Li You really couldn't figure it out.

There are not no strong people who rely on mental arithmetic to find the third power, but Li You is not one of them.

However, what Li You was waiting for was exactly such an opportunity.