How to break into a math book

For such levels that require mathematical calculations, it is often easy to fall into a fixed mindset.For example, the problem of passing through the five doors, they are indeed in the right direction at the beginning, the opening interval of each door is different, and there is a common multiple relationship between these times, the time for the five doors to open at the same time is the number of time least common multiple of .

但他们却被最小公倍数的计算方法禁锢住了。五扇门开合的时间依次是1分45秒、1分10秒、2分55秒、2分20秒和35秒，以35秒为一个时间单位，他们很容易将这五个时间转换成3、2、5、4、1个时间单位。

想要五道门同时打开，就需要等待3、2、5、4、1的最小公倍数，也就是60个时间单位。但眼下的问题并不是等待的时间太久,毕竟他们只要一直呆在第一道门后面,警报声是无论如何也不会响起的,即使在第一道门后等待一个小时也没关系,因为警报声响起的触发因素是：离开第一道门2分30秒。

So the real problem they need to face is not to shorten the waiting time, but to find a way to pass through the five doors within 2 minutes and 30 seconds. After 35 minutes, even if the five doors were opened at the same time, they could not pass through due to the distance.

但只要脱离了最小公倍数的思维定式,这个问题就迎刃而解了。2分30秒中最多包含4个35秒，也就是说他们有4个时间单位的时间离开第一道门，且不会触发警报声。

This means that they have to pass through the other four doors in addition to the first door within 4 time units.It is impossible for them to run so fast and pass when the four doors are open at the same time, but they have a waiting period of 4 time units, which means that they can leave 35 seconds of travel time between each door to ensure that the door and the distance between doors.

沈思易分析道：“五道门的打开时间分别是3、2、5、4、1,我们只要寻找连续相隔一个时间单位的时间段通过就可以。”

“而在60个时间单位内,恰巧在第33、34、35、36、37个时间单位的时候,这五道门会按照先后顺序开启。因为33是3的整数倍，34是2的倍数，35、36、37正巧是5、4、1的整数倍。”

Tu Hua instantly enlightened: "You mean that at the 33rd time unit, that is, when the first door is opened for the 11th time, we will pass through the first door first, wait for 35 seconds, and at the 34th At 17 time unit, the second door happens to be opened for the 2th time, and we pass through the second door at this time. By analogy, we happen to be able to pass through the fifth door while waiting for 20 minutes and 37 seconds, and the fifth door is the [-]th open again."

Shen Siyi nodded, and concluded: "That's right, it actually has nothing to do with our waiting time behind the first door. The key is that we need to find the time when the five doors will open in sequence."

"In the 33rd time unit, when the first door is opened for the 11th time, we pass through the first door and come to the middle of the first door and the second door. At this time, the time we leave the first door is 0 seconds; at the 34th time unit, when the second door was opened for the 17th time, we came to the middle of the second door and the third door, and the time we left the first door was 35 seconds; at the 35th time unit, that is, when the third door is opened for the seventh time, we come between the third door and the fourth door, and the time we leave the first door is 7 minute and 1 seconds; and at the 10th time unit, That is, when the fourth door opened for the ninth time, we came between the fourth door and the fifth door, and the time passed by 36 minute and 9 seconds; wait for another 1 seconds, and the fifth door will open."

"So at 2 minutes and 20 seconds, before the sirens went off, we had already escaped from this prison."

The three carefully calculated according to Shen Siyi's method, waited for a long time, and finally started the escape plan when the first door was opened for the 11th time.

Sure enough, as Shen Siyi expected, the five doors opened in sequence at intervals of 35 seconds, and they escaped smoothly at 2 minutes and 20 seconds.

There were no police officers guarding the gate of the prison. The three wanted to stay away from the place of right and wrong as soon as possible, but they saw a reference room in the aisle next to the prison.The most important thing is that the door of the reference room is open, and there is no one around, as if waiting for them to go in and visit.

Sun Wei grabbed Tu Hua and Shen Siyi, hesitated for a while, and said, "I think there is a reason why the police arrested us involuntarily. The system will not simply let us clear a prison escape mission, there should be a prison in the police station. Clues related to the main case."

Tu Hua looked towards the reference room: "You mean... there are clues in the reference room?"

To be on the safe side, the three of them discussed it. Shen Siyi patrolled the corridor while Sun Wei and Tu Hua went in to look for any clues related to the case.

They had successfully escaped from the prison. It stands to reason that the siren should have sounded long ago, but what is strange is that there was no commotion in the police station, not even a patrolling police officer.

This is so abnormal.

But they didn't think about it that much. Since no one came, it gave them a good chance to find clues.Tu Hua and Sun Wei took this opportunity to turn the reference room upside down. There are many clues and information on old cases displayed in the reference room. It seems that the information on the murder case in the Oma mansion has not been updated. Discover relevant clues.

Just when they were about to give up, Tu Hua suddenly saw a kraft paper bag on the shelf in the corner, with a few words written on the cover of the bag: The two killer teams, Alan and Bryan, fought each other.

This case seems to have nothing to do with the Omar mansion murder case, but the name of the suspect appeared.Holmes once told them that it was two of Alan, Bill, Caesar and Brian who killed Mr. Omar.

Tu Hua quickly opened the brown paper bag, the documents inside were very old, and there were a few blurred photos.Although the clue information seems to be complicated, the closing statement is very clear.

Regarding the case of the two killer gangs fighting each other, it is recorded in the document as follows: Alan and Brian are the leaders of the two killer gangs respectively, but the two gangs have conflicts due to their interests, this time the mutual assault is a contradiction caused by intensification.

The process of the case is not important, but the police detective's seemingly ironic conclusion of the case has attracted Tu Hua's attention.Bill was Caesar's apprentice, and the two didn't belong to any gang, but Caesar and Bill got involved in this fight because Caesar was a fanatical admirer of Brann.

It was also because of this case that Caesar and Allen had a mortal feud. The detective believed that the two would never cooperate in the future.

This seemingly nonsensical inference is actually the clue to the murder case in the Omar Mansion.

Since Caesar and Allen have enmity, it is absolutely impossible for these two to act together.So if one of the people who killed Mr. Omar was Allen, it is absolutely impossible for the other person to be Caesar.Although this is just a simple method of elimination, it narrows the scope of their reasoning again.

The first clue they got in the bar was that one and only one of Bill and Allen went to the Omar Mansion, and in this reference room they got a clue that Allen and Caesar could not appear at the same time, Tu Hua faintly felt , As long as they get one or two more key clues, they can deduce who the two killers who entered Oma's mansion are.

He was about to share the good news with his two teammates when he heard Shen Siyi who had been standing at the door suddenly poked his head over and whispered, "Someone is here!"

Shen Siyi quickly hid in the reference room and quietly closed the door.The three of them searched for a corner to hide, Tu Hua turned off the light, and hid in the container in the corner, Shen Siyi hid behind the door, and Sun Wei hid beside the bookshelf.

The surrounding temperature suddenly became very low, and the faint sound of footsteps gradually approached them with a gloomy atmosphere.There was only a "bang", and the door of the reference room was directly overturned by a powerful force.

Tu Hua hid in the cabinet, and saw the person entering the reference room through the gap in the door.

To be precise, he is not like a human being, but rather a messenger of death from hell.He was at least two meters tall, with a black cloak on his body, his facial features looked as sharp as an eagle, and he was surrounded by a dense chill.

Because the door had already been removed by him, Shen Siyi who was hiding behind the door was grabbed by him, and Sun Wei who was next to the bookshelf was instantly grabbed by his collar, and he grabbed the two of them with both hands, his strength was too strong , Shen Siyi and Sun Wei had no power to fight back at all.

Tu Hua never expected that such a surreal character would appear in this deduction level. Seeing his teammates being hurt, he didn't care about thinking at all. kicked him in the chest.

With Tu Hua's current strength, no NPC could stand against him, but this eerie and strange person remained motionless under Tu Hua's attack.

He looked at Tu Hua with cold eyes, and finally said with a sneer: "All the people are there? Then... welcome to the prophecy of the god of death."

grim Reaper?So... this person is the god of death?

With a sound of "bang dang", the man who claimed to be the god of death suddenly threw Shen Siyi and Sun Wei to the ground. Tu Hua hurriedly rushed to help them, but found that there seemed to be some kind of enchantment between the three of them, and Tu Hua was blocked. Can't get close at all.

Shen Siyi also noticed this strange phenomenon, he helped Sun Wei up, stood opposite Tu Hua, and signaled him not to worry.Tu Hua forced himself to calm down, looked up at the God of Death: "What do you want to do?"

The god of death laughed, and his voice was distant and empty: "Some people's lives have long since come to an end, and the purpose of my coming is to take them away. Mr. Omar was taken away by me, but from your human point of view, the two A killer is a real executioner."

Tu Hua vaguely smelled a hint of danger: "Do you know who the murderer is?"

"Don't worry, kid, play a game with me." The Grim Reaper smiled sinisterly, "I will tell you the information about the two killers, and I will also... take away those who don't belong to this world from among you."