How to break into a math book

Although everyone is skeptical about this simple odd-numbered column, no one can come up with a better sorting method under the current conditions, so we can only bite the bullet and try it.

按照3、5、7、9、11、13、15的顺序排列,除了6号涂化、17号隋利和12号女生之外,其余七人按照顺序站在了指定位置上,等待系统判定。

【Ding--】

[The first round of ranking was wrong, please vote to eliminate one person. 】

After the system judged, the boy No. 13 who always advocated the odd column felt a little embarrassed. After all, it was because of him that everyone wasted an opportunity, and scratched his head in embarrassment: "Now at least we can prove that in our team of 7 people, including Interfering items."

Girl No. 3 scoffed, "It's the same as not saying anything."

"The important thing now is that we must confirm who the interferer is." Sun Wei interrupted the dispute between the two in time, "We now know very few conditions, but we must find someone who must be the interferer based on these conditions. "

Boy number 13 shrugged: "That's number 3!"

3号女生正准备反唇相讥，17号隋利突然道：“如果只按照【如果没有3】这一条信息判定的话，除了3号之外，6号、9号、12号、13号和15号都有嫌疑，因为我们不知道这个3是以什么形式表现出来的,所以包含3和被3整除的数字都有可能。”

Number 3 gave him a grateful look and agreed.

Sui Li continued: "Since these six people are all suspects, then please explain your own views and try to convince everyone."

"Wait." Shen Siyi said suddenly, "I think your statement is a bit one-sided."

“【如果没有3】中的这个3不仅可以表示数列每一项的数字，还可以代表项数以及通项公式中计算的数字。”沈思易分析道,“我可以说这个3是3号,也可以说这个3代表的是3个人,甚至对每个数字加3减3都是合情合理的。如果只根据这一条线索武断的指出干扰项，就太草率了。”

Sui Li glared at him unwillingly: "According to what you said, everyone is suspected, so how can you determine who is the interferer?"

"Now is not the time for retaliation and internal strife." Tu Hua glanced at Sui Li, "We must consider all possibilities, because the selection of the person eliminated by the interference item is not only related to the fate of the selected person, but also to the fate of the selected person. the fate of all of us."

"Once the wrong choice is made, all ten of us will be eliminated together."

Girl No. 12, who was excluded in the first round together with Tu Hua, said: "In addition to the condition [if there is no 3], you seem to have overlooked a very important point, which is the law between our 10 numbers. "

“对于10个数字3、5、6、7、9、11、12、13、15、17，仔细观察一下就会发现，总共有两组连着出现的数字：5、6、7和11、12、13。”那女生淡淡道，“我觉得这两组数字的出现并不是巧合。”

"Sequences that we are often exposed to rarely have such continuous numbers, but there are two groups of such numbers in these 10 numbers, which is likely to be related to the regularity of the sequence."

“而经过进一步验算，我发现5、6、7三个数字的和是18，11、12、13这三个数字的和是36，按照相差18的规律，我认为接下来的三个连续数字应该是17、18、19，而这三个数的和正好是54，与上一组数字之和36正好相差18。”

12号女生给出的方法和理由让人无法反驳：“18是3的倍数，而我选择的这组5、6、7、11、12、13、17的数列，正巧也不包含3号。”

No. 3 looked unhappy: "So, what's the use of such a sorting method? Can you help everyone identify the interference items?"

No. 12 hooked his lips and smiled: "Although I can't confirm it, I have at least provided a way of thinking. I believe that everyone will have the most suspicious person in their hearts based on the information [if there is no 3]."

Number 3 suddenly turned pale.

Tu Hua looked at everyone calmly. He knew that with the current conditions and information, all reasoning was just guesswork, and all the statements made by everyone were nothing more than psychological warfare.Unless a person can be eliminated correctly, for these 10 numbers, he can make up 3 sorting reasons that meet [if there is no [-]].

These people's speculations and exclusions are just because they don't want to get angry.

No one can be sure who the distractor is, but there must be a most skeptical person in everyone's heart.

Indeed, according to all the known information so far, girl No. 3 is most likely to be voted out.Ten people have different ideas, and soon, it's time to vote.

The way to vote is to choose anonymously through the system interface. After hesitating for a while, Tu Hua chose No. 3.

Sure enough, most people thought the same as him, No. 3 won 7 votes, and the most votes were eliminated.

With a pale face, she didn't say anything more, she closed her eyes tightly, as if she never wanted to see this cruel world again.Soon, girl No. 3's body turned into pixel particles and disappeared.

The remaining 9 people held their breaths and prayed secretly for the system's verdict.

【Ding--】

[The game continues, please proceed to the second round of sorting. 】

Everyone heaved a sigh of relief. The game can continue, which proves that their judgment is correct. No. 3 is indeed one of the interference items.But for the condition [if there is no 3], they can only rule out a number 3, and they are still confused about the other two interference items and the order of the sequence.

But the only condition given by the system is only to exclude a number 3... It seems a bit tasteless.

"The conditions given by the system should be more useful than that." Sun Wei had the same idea as Tu Hua, and she analyzed, "I think that in addition to excluding the numbers related to 3, it may also be skipped in the calculation rules of the sequence." 3."

“首先我们从剩下的9个数字中筛选出与3无关的数字。按照刚刚我们一直认同的数字中包含3和3的倍数这个规律来判断，真正与3无关的数字只有4个：5、7、11、17。”

Although Sun Wei's idea is very bold: "Next, we arrange the numbers in order of their size, and soon we can find that there is an operation law of 'skip 3' among them."

"For the first number 3 that has nothing to do with 5, the number 6 that follows it happens to be 1 greater than it; for the second number 7, the number 9 behind it is 2 greater than it; and for the number 11, according to the correct law Calculate, the number behind it should be 3 greater than it, that is to say, the number should have been 14."

“但我们的队伍中并没有14这个数字，结合【如果没有3】这条线索考虑，在计算规律的过程中跳过3，这就证明11后面的数字应该是比它大4的15。”

“这样一来，正确的7个顺序数字应该是5、6、7、9、11、15、17，而跟在17后面的数字应该是比**5的22。”

Compared with the sequence proposed by girl No. 12, Sun Wei's arrangement is obviously more convincing, because she not only excludes the numbers related to 3, but also applies the condition of [if there is no 3] in the sequence law .

But Tu Hua always felt that something was weird.

He felt that Sun Wei's answer was a little far-fetched, but he still couldn't find out where the crux of the problem was.Out of trust in his teammates and the fact that they will have the opportunity to continue answering questions later, Tu Hua did not raise any objections, but agreed to arrange them in the order of Sun Wei.

Except for No. 12 and No. 13, the remaining seven people stood in their positions in order, waiting for the system's decision.

But the expected customs clearance notice did not come.

【Ding--】

[The second round is wrongly sorted, please vote to eliminate one person. 】

Sun Wei looked solemn.Wang Boyu on the side suddenly reacted, and he was a bit afraid to confirm: "The law of the sequence...should be able to judge all the numbers that follow?"

Sun Wei was taken aback for a moment, and finally realized where her mistake in judgment was.According to the law she just guessed, apart from the 10 numbers given by the system, the next numbers in the sequence cannot be completely determined.

5、7、11、17这4个与3无关的数字是从系统给出的数字中挑选出来的，并不存在普遍规律。也就是说他虽然可以确定这些数字两两之差为1、2、4、5……但并不能确定起始的那个数字是什么。

跟在17后面的数字是使其差为5的22，但22后面的与3无关数应该是什么？前面的几个数字并不存在这样的规律。

So the sequence she proposed is not exactly a sequence, but simply looking for patterns among the 10 numbers provided by the system.

"So, who should we eliminate next?" Sui Li looked at them contemptuously, with mocking eyes.

Things seem to be back to square one.

They still haven't found the real law belonging to this sequence, that is to say, they still can't judge the remaining two interference terms.

The message must be in the sentence [if there is no 3].

So what does this hint mean?It is absolutely impossible to rule out such a superficial law as the number 3, and this sentence must contain a deeper meaning.

If there is no 3, if there is no 3... From a linguistic point of view, this is a hypothetical sentence pattern.

"If" usually expresses people's assumptions and expectations about something, that is to say... [If there is no 3] the real meaning is: there are 3!

Tu Hua was stunned, and checked the remaining 9 numbers in his mind, and the answer was ready to come out.

But the answer is...

Tu Hua looked up at Wang Boyu, who looked carefree, and saw Shen Siyi standing beside him.And Shen Siyi was also looking in his direction, his face was solemn, and there seemed to be a little worry in his eyes.