After Dressing as a Male Cross-dresser

The final result did not surprise everyone.

It was Fan Mingcheng who finished the calculation first.

After he handed in the paper, he glanced lightly at Jin Xiangjun and Li Qingyan.

Li Qingyan didn't know what Jin Xiangjun thought.

But in Li Qingyan's eyes, there is always a sense of ambition for a villain.

Sure enough, she didn't like Fan Mingcheng such a narrow-minded, jealous and capable person.

Dr. Lu didn't have much joy on his face either. He was unhappy about the supervisor who hadn't chosen "difficulty".

No vision!

Soon, it was the turn to choose the "medium" batch of supervised students.

As soon as the screen was removed, the question soon appeared in front of everyone.

Li Qingyan narrowed her eyes slightly, trying to see the topic clearly.

But this is a bit interesting.

The title of "中" was written in classical Chinese and translated into modern words.

that is--

You want a team of craftsmen to repair the bridge for you for seven days. The return you promised to this team of craftsmen is a silver bar. You must settle your wages to the foreman at the end of each day, but this silver bar is only allowed to break two. Back, may I ask, how do you pay for the foreman?

As soon as this question came out, everyone who chose "middle" immediately fell into contemplation.

Li Qingyan looked at the people's worrisome faces, but there was a flash of enlightenment on her face.

However, considering that there was no such concept of "geometric sequence" in ancient times, I really need to think more about it.

Among them, the solution to this problem is not difficult.

First, measure the silver bar with a ruler, divide it into seven equal parts, and mark them.

Then divide the silver bars into one, two, and four ratios.

In terms of fractions, it is one-seventh, two-sevenths, and four-sevenths.

On the first day, cut one-seventh of the silver bar and give it to the foreman.

On the next day, cut off two-sevenths of the silver bars, give the silver bars to the foreman, and then take back the previous one-sevenths of the silver bars.

On the third day, one-seventh of the silver bullion was given to the foreman. At this time, the foreman had three-sevenths of the silver bullion in his hands.

On the fourth day, give the remaining four-sevenths of the silver bars to the foreman, and take back the "three-sevenths" of the silver bars that the foreman has combined with the "two-sevenths and two-sevenths."

On the fifth day, the foreman already had four-sevenths of silver bars in his hands, so he only needed to give him another one-sevenths of silver bars.

On the sixth day, the silver bar combination in the foreman’s hand was "four-sevenths and sevens." There are six sevenths of silver bars.

On the seventh and last day, the last "one-seventh" silver bar was given to the foreman, and a complete silver bar was given to the foreman.

In the whole process, the permutation and combination of the three silver bars of "one-seventh", "two-sevenths" and "four-sevenths" were used to pay for the wages.

And the result of this derivation can be calculated using the "geometric sequence".

However, it is not difficult for Li Qingyan, who has studied modern mathematics, and it is still a bit difficult for this group of supervising students in ancient times. At least the first of them thinks for a quarter of an hour longer than Li Qingyan.

This first person, Li Qingyan was not surprised at all.

It is Jin Xiangjun.

The answer is similar to what she just analyzed.

However, Jin Xiangjun's answer was so quick and accurate, it made Dr. Lu and the supervisors on the scene a jump in their hearts.

Because Li Qingyan knew the simple solution, she was uncertain about the difficulty of this problem.

Dr. Lu thought it would take half an hour for someone to solve it. Unexpectedly, Jin Xiangjun would solve it in a quarter of an hour.

He looked at her a few more times.

But my heart turned around.

With this level, why not choose the most "difficult" one?

No one cares about Dr. Lu's "good heart", and it really becomes a piece of his heart disease.

However, Dr. Lu is very confident in his "good heart", even if Li Qingyan may have some skills, it should take more than a quarter of an hour.

Perhaps longer, Dr. Lu decided that if Li Qingyan delayed too much time, he would let Fan Mingcheng and Jin Li take the second test first.

When the screen was removed, Dr. Lu raised his chin somewhat triumphantly, as if to show his treasure to everyone.

This is because he accidentally found the title on a long-lost ancient book. At that time, he saw it was very subtle, and now he wanted to change the title and put it into the assessment.

Sure enough, as soon as his topic was revealed, everyone's faces appeared astonished. Even Fan Mingcheng and Jin Xiangjun, who had previously passed "Yi" and "Zhong", frowned suddenly and fell into contemplation.

Although the two of them did not choose "difficult" for various reasons, they were also looking forward to the topic.

At first glance this time, it really made the two of them difficult.

Not to mention, there are a lot of "numerical" students who are not proficient in supervising students.

However, even Bai Jingshu, who is proficient in "numeracy", raised his eyebrows slightly, and said with Ji Fei beside him.

"It really can be called a problem."

But in Li Qingyan's view, this question also...

It's too simple.

The title is like this-

"I don't know the number of things today, two out of three or three, three out of five or five, and two out of seven or seven. What is the smallest thing?"

Li Qingyan has seen this question, the original question is from "Sun Tzu Sutra".

Translated into modern means--

There is an integer, it is divided by 3 with remainder 2, divided by 5 with remainder 3, divided by 7 with remainder 2, find the minimum value of this integer.

The original question did not seek the minimum value. When Dr. Lu wanted to come, he wanted a specific number and added it.

If Li Qingyan used modern methods to do it, it would be a matter of formulating a few equations.

Assume that the integer is N.

but:

N=3X2

N=5Y3

N=7Z2

Coupled with Dr. Lu’s finding the minimum value of this integer, and once the three equations are solved, we can know that this integer is 23.

Although the answer that did not seek the minimum value in "Sun Zi Suan Jing" is also given as 23, it is inaccurate in later generations. The accurate value should be "23(3*5*7)*m".

Of course, it is not difficult for Sun Tzu to calculate the number given by this question. You can try to figure it out, but since Dr. Lu has asked this question, he must solve it.

The simple version of the solution to this problem is mentioned in "Sun Tzu Suan Jing", but there is a systematic solution in the subsequent "Nine Chapters of Mathematics: Dayan Qishu", and it is another great achievement in the history of ancient Chinese mathematics— —

Chinese remainder theorem.

It is one of the four major theorems of number theory.

Although not as well-known as the "Pythagorean Theorem", it is indeed another great achievement in the history of ancient mathematics.

Li Qingyan was thinking about the history of the remaining theorem silently, and there was a trace in his eyes, no wonder he put it in the "difficult" category.

But since it is seeking the "minimum value", just use the simple version in "Sun Tzu Suan Jing".

In her impression, the "Sun Zi Suan Jing" of this era is in a state of being lost, and there is no such concept of unknown number. However, looking at Dr. Lu's enthusiastic appearance, the title is not too different from the "Sun Zi Suan Jing". Many, it seems that this book has fallen into his hands.

Although there were many thoughts, Li Qingyan quickly figured it out. In the eyes of outsiders at this time, it was not even a minute.

Li Qingyan raised her eyes slightly, and her eyes fell on Dr. Lu from the subject.

Then he arched his hands and said lightly.

"Dr. Lu, the student has an answer."

As soon as this was said, the audience was quiet.

Before the triumph on Dr. Lu's face was gone, he was shocked.

He has a good heart. He has been blindfolded and solved for a while. How can Li Qingyan solve it so quickly?

Did you try it out?

Can that be called "arithmetic"? !

Dr. Lu blew his beard a little unhappily and reminded him.

"This official wants a specific solution."

Li Qingyan still did not change her expression.

"That's natural."

As soon as the voice fell, everyone took another breath, and even Bai Jingshu's face was shocked for a moment.

He hasn't thought of a solution to this problem yet, of course, it is impossible to think of a solution in such a fast time.

When Dr. Lu saw what he had said, he was really curious about whether Li Qingyan could really answer it, so he gently folded his hands and said with Li Qingyan.

"So, come and listen."

As soon as Dr. Lu finished speaking, everyone's ears were pricked up.

It was all about how Li Qingyan solved the problem, because none of them was there to solve it in such a short time.

Li Qingyan was not flustered at all, standing straight, with a calm expression on her face.

"The answer is twenty-three."

"The remaining two of the three-three number is set to one hundred and forty; the remaining three of the five-to-five number is set to sixty-three, and the remaining two of the seven-seven number is set to thirty. If one is subtracted from ten, it is obtained. If the remaining one of the three or three numbers is one, it is set to seventy; the remaining one of the five or five numbers is set to 21; the remaining one of the seven or seven numbers is set to fifteen; more than one hundred and six You can get it by subtracting one hundred and fifty."

This is the answer in "Sun Tzu Sutra".

It means that according to the question "there is an integer, divided by 3 will remain 2, divided by 5 will remain 3, divided by 7 will remain 2", we can find three numbers first.

There are three conditions in this subject-

"Divided by 3 will remain 2"

"Divided by 5 will remain 3"

"Divided by 7 will remain 2"

Then we will break down the conditions one by one.

First find the number of remaining 1 after dividing by the other condition assuming that two of the conditions are divisible.

The first number can be divisible by 5 and 7, but divided by 3 leaves 1, which is 70.

The second number can be divisible by 3 and 7, but divided by 5 remains 1, which is 21.

The third number can be divisible by 3 and 5 at the same time, but divided by 7 leaves 1, which is 15.

To put it simply, if you divide by 3, add as many as 70, divide by 5 and add as many 1, then as many as 21, divide by 7, add as many as 15.

Go back to the subject condition "divide by 3 and remain 2, divide by 5 and remain 3, divide by 7 and remain 2".

Then (7070), (212121), (1515).

Then three numbers of 140, 63, and 30 will be obtained. Adding the three numbers is equivalent to adding three conditions to get "233", that is, the number 233 satisfies these three conditions at the same time.

But because of the minimum value, "233" minus "3*5*7" multiplied by a multiple is less than the maximum value of "233", that is, "3*5*7*2=210", 233 minus 210, you get 23.

The method in "Sun Tzu Suan Jing" is actually very cumbersome to use ancient mathematics thinking to understand, but it is true that in such a difficult mathematics environment at that time, such a powerful algorithm conclusion can be drawn, and the wisdom of the ancients is also impossible. Underestimate.

Li Qingyan finished speaking in one breath, fearing that the classical Chinese text was too short, so she also translated her big vernacular into classical Chinese and explained it.

It can be said to be rare and easy to understand.

Dr. Lu's obvious choking expression can be seen.

Not to mention the surrounding prison students, nodding their heads uncontrollably.

So it can be solved like this.

However, in this, there are a few people with very different expressions.

Fan Mingcheng looked unconvinced, only that Li Qingyan must have seen similar topics before, otherwise how could it be completed in such a short time.

Although Li Qingyan knows this question, she knows how to answer it even if she doesn’t read the original question. Not to mention, in order to apply ancient thinking to the answer, she struggled to figure out how to rely on ancient mathematical thinking, and don’t say too advanced theories. .

On Li Qingyan's troubles with modern mathematical thinking.

Jin Xiangjun is a look of admiration, and only feels that Li Qingyan is more than just "the number one talent in Shengjing" in the Great Yan Dynasty, and she is already "the number one talent in the world" in the country where she lives.

Of course, because of Jin Xiangjun's possessiveness to the people she likes, Li Qingyan's such a powerful side, she just wants to monopolize, not to share with everyone.

Therefore, there is a trace of regret and unhappiness in Jin Xiangjun's eyes. After all, it is not her dynasty, and she can't stop many things.

But the shock in Bai Jingshu's eyes has not disappeared for a long time.

In my mind, I suddenly remembered that my head hurt from studying "numeracy" a few months ago, so I put aside the cruel words and said that I don't want to touch the figure of "numerology" anymore.

Bai Jingshu's eyes fell on Li Qingyan, who was greatly admired by everyone on the court.

Is the person in front of you really... Ayan?