Lin Wan Yi's steps stopped at the staircase.
She held her book and slowly turned around.
The elderly professor with graying hair had already pushed through the crowd, rushed up to the blackboard in just a few steps. He adjusted his reading glasses on his nose and nearly pressed his face to the board, muttering incessantly, "Martingale method... Yes, it's the martingale! Directly from the essence, bypassing all complex integral transformations... Genius! This thinking is simply genius!"
The surrounding students hardly dared to breathe.
"It's Professor Qian! Professor Qian Xuezhang from the mathematics department!"
"Oh my, this question even startled Mr. Qian!"
An uncontrollable exclamation arose from the crowd. Qian Xuezhang, the pillar of Beijing University's mathematics department, a leading figure in the field of probability theory in the country. The weekly problems he posed, those who could solve them were the top talents of the department.
