How many integers from 1 to 500 inclusive are
(a) divisible by 6, but are divisible by neither 8 nor 10?
(b) divisible by 6 or 8, but are not divisible by 10?
(c) divisible by 6 and 8, or are not divisible by 10?
a) Prove by induction that if a product of n polynomials is
divisible by an irreducible polynomial p(x) then at least one of
them is divisible by p(x). You can assume without a proof that this
fact is true for two polynomials.
b) Give an example of three polynomials a(x), b(x) and c(x), such
that c(x) divides a(x) ·b(x), but c(x) does not divide neither a(x)
nor b(x).