Simplifying state whether the number is a rational number or an irrational number?

If n is a rational number, then units digit in 6ⁿ – 5ⁿ is:

If is a rational number, then what will be the condition on q when is a terminating decimal?

Show that any positive odd integer is of the form 4q + 1 or 4q + 3. Where q is some integer.

Prove that the product of two executive positive integers is divisible by 2.