Answers to Questions as You Grow Up:

Why are there three toilets?
10 years - I don't know if someone wanted and put them exactly 3.
20 years - I know... there is a science that says how many toilets are needed in the toilet.
25 years, I know. They are exactly 3, because there is a regulatory calculation in the SNiP Public Buildings, and it is stated that 3 toilets are required for this building area.
30 years, I doubt it. The SNIP is old, and that calculation seems to be wrong... because there are options where these toilets will be exactly more than you need... or less than you need.
35 years old - I'm almost sure the number of toilets cannot be determined accurately. There are different regulatory documents regulating the number of toilets on such a building area, and it is not known exactly which one is in effect at the moment to take it as the basis.
40 years - I know for sure that even if taken as the basis of any of the existing regulatory documents, it is impossible to determine how many of them should actually be and who has built: the one who designed, the one who built or the one who took the work.
50 years - I don't know anyone wanted and put them exactly 3.