enjoyebooks Chapter 24 Dr. Geng's Debut
Chapter 24 Dr. Geng's Debut
The arguing next door finally subsided, but Geng Zhi tragically discovered that his meager sleepiness had completely vanished.
To force himself to fall asleep quickly, he had a sudden inspiration and grabbed the book "Complete Review Book for Postgraduate Entrance Examination Mathematics" by Li Yongle, which he had just used to record his crazy ideas.
I haven't touched this thing in over a decade. Doing a few challenging math problems should have a hypnotic effect, right?
Thinking this through, Gengzhi closed his eyes and randomly flipped to a page—deliberately turning to a page near the end of the book.
Logically, the questions should become more and more bizarre as the book progresses.
Sure enough, he came across a lengthy question on probability theory and mathematical statistics.
The question is as follows:
In Las Vegas, a taxi driver caused an accident at night and fled the scene.
The city has only two taxi companies; one has all red vehicles, and the other has all white.
[It is known that 85% of taxis in Las Vegas are red and 15% are white.]
An eyewitness identified the taxi involved in the accident as white. That evening, security personnel tested the eyewitness testimonies at the scene of the accident and concluded that the probability of the eyewitness correctly identifying the two colors at the time was 80%, and the probability of being wrong was 20%.
Q: Based on the information above, what is the probability that the taxi involved in the accident was white rather than red?
Geng Zhi was only slightly tired, but the moment he finished reading this question, he not only didn't feel sleepy at all, but his eyes lit up, his spirits lifted, and he was wide awake!
He sat up abruptly, quickly grabbed paper and pen, and transformed into Dr. Geng, entering a state of complete concentration on examining the question, recalling, and deducing.
This question... should be a typical application of Bayes' theorem, right?
Ultimately, what needs to be calculated is the posterior probability that "the car is indeed white," given the condition that "the witness claims it is white"...
Event A: The taxi was actually white; Event B: Witnesses claimed it was white...
My brain was working at lightning speed, and the pen tip traced clear formulas across the paper.
About a hundred seconds later, a number appeared on the paper: 41.379%.
With a hint of curiosity, he turned to the answer key page at the end of the book. There it clearly stated: 【12/29】.
Converted to decimal, that's exactly 41.379%!
"Tsk..."
It seems that after sixteen years, I haven't completely forgotten all the math I learned from my teacher.
Dr. Geng's lips unconsciously curled up into a smile of accomplishment, expressing satisfaction with his mathematical debut.
Filled with anticipation for tomorrow's visit, he quickly drifted off to sleep.
......
The next morning, a ray of golden sunlight streamed through the window without restraint, landing precisely on Geng Zhi's face.
Geng Zhi slept soundly until he woke up naturally, slowly opening his eyes.
The first thing I felt was the almost surging vitality in my body—there was no heaviness after staying up all night, no strain of getting up early in middle age, and inexhaustible energy flowing through my veins.
I feel like I'm 20 again after being 36! My fatty liver is gone, my neck pain is gone, and even the energy I feel when I wake up in the morning is so exhilarating... It's so good to be young!
After washing up, Geng Zhi jogged straight to the First Dining Hall of Shanghai Jiao Tong University.
In his past life, he had visited Shanghai Jiao Tong University once. At that time, he was working at a chrysanthemum factory and came to the campus to recruit and promote the company's campus recruitment team.
They came and went in a hurry, and what impressed him most was the big plate of chicken noodles at the First Catering Building.
Returning to the same place, he ordered two meat buns, a tea egg, and a cup of soy milk for breakfast, which only cost him two yuan and thirty cents!
Since Geng Zhi is not a student at the university, he had to pay in cash, so the restaurant charged him an extra 30 cents for management fees. If a student from Jiaotong University were to use their campus card, it would only cost 2 yuan.
After breakfast, he went to the campus print shop to print out Professor Qi Chuqin's key papers that he had downloaded the night before.
Immediately afterwards, I found a study room near Professor Qi's office, and while marking up the papers, I rehearsed the key points of the conversation that would follow.
One of Qi Chuqin's research areas is GIS (Geographic Information System), and his alma mater, Jiangcheng University, is not only the best in China in the field of GIS, but also at the top level in all of Asia.
As a doctoral student who received systematic GIS training at Jiangcheng University in his previous life, he also has a deep understanding of GIS.
Therefore, when reading Professor Qi's papers on this topic, I found it quite easy.
At 9:45, Geng Zhi calmly got up, straightened his clothes, and walked towards Professor Qi Chuqin's office.
……
The office door was ajar, and through the crack, Geng Zhi saw Professor Qi Chuqin hunched over his desk, sketching something on a piece of paper with a focused expression.
He didn't barge in rashly, but stopped at the door and gently knocked on the door.
"Hello Professor Qi, I'm sorry to bother you."
"Hey, Xiao Geng's here! Come in, come in!"
Qi Chuqin looked up upon hearing the voice, a warm smile immediately spreading across his face. He put down his pen and waved repeatedly to Geng Zhi.
Geng Zhi strode in and handed Professor Qi Chuqin a paper bag of lilies he was carrying:
"Professor Qi, these are some local specialties from Lanzhou that I specially brought with me before I left. The lilies grow on the Loess Plateau and have a sweet taste. They're great for making porridge or soup. Please have a taste with your family."
"Oh, you're too kind, child! Okay, okay, I'll accept it, thank you, Xiao Geng!"
Qi Chuqin happily accepted it, casually placed it on the desk, and quickly gestured for Geng Zhi to sit down: "Xiao Geng, sit down."
While Qi Chuqin got up to get water, Geng Zhi's gaze quickly swept across the office.
The office is spacious, but the lighting is not particularly bright.
Two walls are occupied by floor-to-ceiling solid wood bookshelves, crammed full of books: hardcover atlases, thick monographs on GIS principles, and many remote sensing albums with yellowed covers.
On the top shelf of the bookcase, a stack of blue hard-cover folders was piled up in two compartments, making Geng Zhi linger for a couple more seconds.
The words "863" were clearly visible on it, a topic he had dealt with a lot in his previous life at Jiangcheng University.
On the other side of the wall, there is a small LCD screen displaying a 3D digital map of a certain area, with lines and data constantly and subtly changing.
"Here, Geng, have some water. You must be tired from the journey." Qi Chuqin brought over a glass of warm water and handed it to Geng Zhi.
"Thank you, Professor Qi. It's no trouble at all." Geng Zhi accepted the gift with both hands, his posture respectful.
For the next ten minutes or so, Qi Chuqin chatted with Geng Zhi like old friends, talking about their travels, Lanzhou University, and their hometown. The conversation was light and pleasant, and they also briefly discussed a few computer concepts.
However, Professor Qi Chuqin did not mention the topic of postgraduate entrance examination at all, which made Geng Zhi feel a little uneasy.
Surely you don't want to hire me anymore?
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P.S.: Three chapters today! Please read on, leave comments, vote, and give monthly tickets to help this seedling grow strong. Thank you so much! Regular high-volume updates will begin after the book is released!