I have a column, lets call pipeID (this contains 1500 pipeID) these data are
stored in sheet called "original".
I have run a program for damagae analysis of these pipes, 50 times (for 50
scenarios).
I have stroed result for each run in separate sheet.
I have 50 sheets named:run1, run2, …, run50.
In each sheet I have following data: PipeID of broken pipes and pipeID of
leaked pipes. (In each run only few pipe out of 1500 pipes are broken or
leaked, relativley a very small number of pipes)
Now I want to perform a countif command over these 50 sheets separetly for
leaks and breaks, and write result in "original sheet" in front of each
PipeID for leaks and break separately.　

Solution one) Easiest way
I can perform countif for each sheet separately and write result in
"original" sheet, then I can add these 50 cells.

Better solution)
Question one: I was wondering if it is possible to perform countif command
over 50 sheets at ones.

Question 2) My method is very straight forward and easy but with no talent
on it. I would like to know if there is any smarter way to count number of
cells over more than one sheet?