PHP Server balance / load (CPU and memory)

A server has a page that calls 10 different PHP files which in total up take 10 ms (1% of CPU) to execute and 1MB of memory. If the website begins to get lots of traffic and this individual page request that calls these 10 PHP files takes 10 ms (1% of CPU) happens to gain 90 hits per second does the CPU percent increase? Or balances at 1%? Also does the memory increase?

What would the load (CPU and memory) look like at 100 hits? 1,000 hits? 10,000 hits? and 100,000 hits? Keeping with the above specifications.

Also, if there were another 10 different pages, calling 5 unique PHP files and 5 of the same PHP files from the above call? What happens to load at 100 hits, 1,000 hits, 10,000 hits and 100,000 hits per second? Does it partially increase? Balance?

There isn't much information on heavy loading behavior for PHP online, so I'm asking to get a better understanding, of course. Thanks! :o)

Your question has a difficult answer and I cannot tell you the accurate ratio of the increase of server's resources. But, keep these two things in mind:

1. More the number of users, more the use of resources. So, it doesn't matter that you are calling the same files, but the thing which matter is that you are calling it 90 times.
2. Your system's usage would increase definitely, but one thing would make it a little less. And, that is caching. Your CPU would load these files into its cache (when they would be accessed very much) and hence, it would make the process a bit faster.