In the early days of the founding of New China, Tsinghua University's facilities were relatively backward, coupled with its remoteness, and at that time, the financial allocation for scientific research funds was relatively small compared with many schools. At that time, Tsinghua was far from its present status, so many children with better family conditions would not choose Tsinghua at that time, while many students in Tsinghua were from rural areas.
Therefore, Tsinghua at that time was "poor" in terms of school conditions and students' family conditions, so it was called "poor Tsinghua".
In the early days of the founding of the People's Republic of China, Peking University was "rich" in both infrastructure and teachers! In addition, Peking University was directly under the government at that time, and the annual education funds were among the best in the country. Many children with superior family conditions at that time would choose to study at Peking University.
Therefore, contrary to Tsinghua, Peking University was "much richer" than Tsinghua in terms of school conditions and teacher-student conditions! That's why it's called "Fubei University".
"Poor Tsinghua is rich in Peking University, and China University of Science and Technology is desperate!" Although it's just a joke, the status of the three schools is definitely the top level of domestic colleges and universities, and the scores of the college entrance examination in these three schools are particularly high every year. Generally, they are not candidates in the top 100 or 200 of the province, so these three schools really can't pass the exam.