Marrying My Bestie's Ferocious Brother - He Calls Me His Baby!-Chapter 132 - 131: A Chance Encounter in the Library, I Casually Solved a Math Department Problem
Lin Wan Yi carried the lunchbox that had been secretly "seasoned" and walked out of the cafeteria calmly under a cloud of complicated glances.
Gu Ning in her arms seemed to smell the aroma of meat, sniffing the air with his little nose, smacking his little lips, and then fell back into a deep sleep.
Back at the quiet little building, Gu Lan was sitting angrily on the stone bench in the courtyard.
"Sister-in-law! That Liu Meiqin is so hateful! If it weren’t for those two comrades coming quickly, I would’ve...!" She waved her small fists, her face full of indignation.
Wang Guihua brought out a basin of warm water from the house, deftly wrung out a towel, and handed it to Lin Wan Yi to wipe her hands.
"You kids, don’t get so worked up." Wang Guihua glanced at Gu Lan, her tone calm yet weighty. "Arguing with such people demeans yourself."
Lin Wan Yi placed the lunchbox on the table and carefully wiped her hands with the warm towel before taking the soundly sleeping Gu An from Gu Lan’s arms.
"Nanny Wang is right," she said softly. "Arguing with a dog—if you win, you’re worse than the dog; if you lose, you’re not even as good as the dog. In any case, it’s a losing deal."
Gu Lan was amused by her analogy and let out a chuckle, dispersing most of her anger.
Lin Wan Yi opened the lunchbox and divided half of the hidden braised pork into Gu Lan’s bowl.
The aroma of the meat spread in all directions.
She looked at the shiny, braised pork in the bowl, her gaze calm.
This trip to the cafeteria taught her a lesson.
People like Liu Meiqin are like flies; kill one, and another will come. The military background can intimidate for a while, but it can’t protect her at all times.
The only way to have peace is to reach a height where all flies can’t approach, not even having the qualification to look up.
She must, in the shortest time, establish absolute, unshakeable authority in this prestigious university.
After finishing the meal and settling the two children, Lin Wan Yi pulled out a pen and paper.
"Sister-in-law, are you going to read again?" Gu Lan leaned in.
"Going to the library." Without looking up, Lin Wan Yi made a list of books. "I’ve finished the materials from the Agricultural College. Some data models and soil chemistry theories require more specialized original books from the Science Faculty."
The place she was heading to was the core area of the Peking University Library—Foreign Language and Science and Technology Reading Room.
An hour later, Lin Wan Yi appeared on the third floor of the library.
It was even quieter here than downstairs, the air filled with the scent of old paper and ink. Few students passed by, each in a hurry, looking serious.
She quickly found the German original "Soil Physicochemistry" and the English "Agricultural Statistics" she needed.
As she was preparing to leave with the heavy books, she passed by an area used for public discussions.
In front of a half-person-high blackboard stood a crowd of over a dozen people, mostly boys wearing thick glasses and looking reserved.
Everyone was staring at a problem on the blackboard, either scratching their heads or arguing in low voices.
At the top of the blackboard was a line of bold handwriting—"Mathematics Department Weekly Challenge: A Probability Problem about Brownian Motion."
Lin Wan Yi casually glanced at it and was about to leave when a sharp and familiar voice sounded in the crowd.
"This problem tests the conditional expectation in a random process and requires the use of Ito’s lemma. Memorizing won’t help solve it."
Chen Zhiyuan stood before the blackboard, holding a piece of chalk, with an air of lecturing. He didn’t write anything but enjoyed the admiration of his fellow students.
His gaze swept through the crowd and landed on Lin Wan Yi, who was holding a stack of books.
He squinted and raised his voice intentionally, with a hint of sarcasm.
"Some people think learning a few farmyard tricks makes them someone important. Seeing a real academic problem like this, I’m afraid they can’t even recognize the symbols, right?"
Upon hearing this, several mathematics students frowned but no one spoke up.
Lin Wan Yi seemed not to hear it, her steps undeterred, heading straight for the staircase.
Chen Zhiyuan, seeing her ignoring him, assumed she was guilty and let a disdainful smile cross his face.
However, as Lin Wan Yi passed by the blackboard, her steps suddenly halted.
She wasn’t provoked by the taunt. It was the stack of books she was holding that was too high, blocking her view, and forcing her to sidestep her way through.
In that brief moment of sidestepping, her gaze fell on the problem on the board.
This brief pause focused all eyes on her.
Chen Zhiyuan’s smile broadened. "What? Can’t understand it, but still want to take another look?"
Lin Wan Yi didn’t look at him.
She simply walked to the blackboard, carrying her books.
The crowd parted for her effortlessly.
She placed her stack of heavy foreign books down lightly and then casually picked up a piece of chalk from the holder.
Chen Zhiyuan’s expression changed, a sense of foreboding welling up inside him.
Everyone watched the "famous figure" from the Agricultural College, curious about what she intended to do.
Lin Wan Yi moved.
Her hand was steady, and the chalk touched the blackboard without a trace of hesitation.
"Swipe—"
A clear and elegant formula flowed out like a stream.
She didn’t use the "Ito’s lemma" Chen Zhiyuan had mentioned to sound profound but directly constructed a simpler martingale method.
Her writing speed was swift, the chalk bouncing on the board, making crisp "tap-tap" sounds. Each step was as clear as printed text in a textbook. The logical chain was seamless, with no superfluous calculations.
"Swipe!"
The last stroke finished.
She drew a decisive horizontal line under the final answer.
The entire process took less than two minutes.
She put down the chalk.
A light "pop" sound was like thunder in the pin-drop silent discussion area.
In front of the blackboard, more than a dozen top students from the Mathematics Department, including the previously boastful Chen Zhiyuan, were all petrified.
They seemed to be under a spell, staring at the few simple lines of deduction on the board, their minds blank.
Just... like that?
Yes, just like that.
Yet why hadn’t they thought of this fundamental and straightforward method all morning?
The color drained from Chen Zhiyuan’s face in an instant, turning ashen.
He looked at the flowing solution process on the blackboard, then at his own drafts full of auxiliary lines and complex integrations, an unprecedented sense of humiliation poured over him like scalding molten iron.
Lin Wan Yi never looked at him, not once.
She didn’t even look at anyone around her.
She simply picked up her stack of books again, turned, and left.
Just as if accomplishing an ordinary task.
As her figure was about to disappear down the staircase, an old yet eager voice suddenly exploded from the back of the crowd.
"Wait! Student! The student who wrote the solution, please wait!"
An old professor with graying hair, wearing reading glasses and a Zhongshan suit, burst through the dumbstruck students like a gust of wind.
He rushed to the blackboard, his hands trembling with excitement as he looked at the solution steps.
"Brilliant! Absolutely brilliant! Reduction to simplicity! This captures the essence of probability theory!"
He spun around abruptly, shouting with all his might towards the direction of the staircase.
"This student! Please wait! Which department are you from?"
