I believe number of results which is returned by Google for each query isn't correct.

[pouya_teh_25]

I believe that "number of results" which is returned by Google for each query isn't correct.

For example: the results of three following queries must be the same. (The result represents number of all pages which is indexed by Google and thus must be unique)
(inurl:w | -inurl:w) number of results: 15,440,000,000
(inurl:a | -inurl:a) number of results: 11,910,000,000
(inurl:n | -inurl:n) number of results: 17,290,000,000
As you can see there is difference between results. And also I want to know is there any way to find out how many pages and files were indexed by google?

Another example: suppose the following queries:
site:com number of results: 4,700,000,000
site:net number of results: 348,000,000
(site:com | site:net) number of results: 4,320,000,000
The number of results for third query must be equal sum of the number of results for two other queries (number of results for third query = number of results for first query + number of results for second query) but unfortunately it's not.

Please just say me what's wrong?
Any help would be appreciated.

[Aleksandr(Sasha)]

There have been several comments like this recently, including the fact that when you use multiple words in quotation marks your results are off by a factor of more or less 500. Perhaps this information should be put in a sticky thread to let people know that the estimated number of results is way off except for when using only keywords?
Edit: for example, try searching

"butter on the right"

. Rather than the 90,900 search results estimated, you only get 31 (43 if you allow repeated search results).

[goodamr]

great point Sasha

[leftybogs]

thats right google usually don't show actual or exact result... estimated result.. just like backlinks...

[x3mario]

It is clearly estimated result...as you see the figure, it all ended with "000" meaning possible that there are next succeeding page...but google won't show it all.