Sofya Aleksandrovna Yanovskaya, a Russian mathematician of Jewish origin of the 20th century  specialist in logic, posed different problems to her students so that they would solve them with perseverance and so that they would continually ask themselves: what am I doing? where am I going? We propose you to solve the following mathematical logic problem.

The zookeeper commented the other day:

- 17 bears eat as much as 170 chimpanzees. 

- 100,000 mice eat as much as 50 chimpanzees. 

- 4 elephants eat as much as 10 bears. 

How many mice would eat as much as 12 elephants?