How many hours a day on Mathematics as a successful student? My motivation to ask this question actually comes from here, receiving negative reactions for 12 hours a day or even 7 hours spending time on Mathematics.

A person usually spends 4.5 years to accomplish a BSc plus a MSc coursework. Books that I found to study in pages (BSc+MSc) approx. are: 


Calculus (760)
Algebra (450+940)
Topology (510+540)
Analytical Geo (210)
Real Analysis (610+520)
ODE (440)
Complex Analysis (480+350)
Differential Geo (510+420)
Logic (260)
Number Theory (480)
PDE (320)
Total: 7800 pages. 


Supposing spending 30 min per page of studying and 2 hours per page of exercises, so it takes  (4/5)×7800×0.5+(1/5)×7800×2 = 6240 hours = 5.5 hours a day in 4.5 years (excl. Sat+Sun) for a student. 

The problem is: 

1- I think that a Mathematics student has to learn more than I have listed, for example other subjects in Mathematics. 

2- a Mathematics student has to spend on other than studying texts, like attending classes, other courses (e.g. computer) as well. 

How a typical university student in Mathematics spends a few hours in average on studying and knows a lot Mathematics and  is able to start research, which I am not capable of? It's a paradox, or maybe I am not smart as other?  

Thank you. 

PS I am not officially a uni student yet, but I had to spend 12 h/d on average to study the mentioned books which I am pretty sure are less than what a uni student covers in their studies.
I am afraid that your computation is not even wrong.  You might as well ask how many hours a day you need to practice dribbling in order to be a professional basketball player.  

Mere knowledge of mathematics is just one component of being a professor, even a professor of pure mathematics.  To become a successful mathematics professor (or any type of professor, really), you need a lot more than just to have studied many textbooks: you need scientific creativity, you need vision, you need to be able to communicate and write well, you need to be able to teach, you need self-discipline, you need some broader understanding of how mathematics fits into the larger world, and you need many more things besides.

Moreover, one of those many things that you need is skill at extracting knowledge from texts.  The deeper your understanding becomes, the more that you will be able to see the structure of the content that you are reading, to analyze which parts are critical and which are accessory, and the less that the computation you present makes sense.

In short: yes, it takes a lot of effort on mathematics to become a professor, but the process and challenges are very different than you think.