Principle of Inclusion and Exclusion

What are the principle of inclusion & exclusion ? ex:- Find the no. of positive integers from 1 to 1000 which are divisible bY atleast 2;3 and 5 .

Dearrangement And Inclusion and Exclusion principle

Problems Based on Dearrangement And Inclusion and Exclusion principle

Which one of the following is not a principle of inclusive education?

Inclusion bodies