1. Because n, r, q and z have no specific numbers, you can't be sure how many elements they contain. So it is an infinite set.

2. Neither of them is right.

Multiply two numbers, where both numbers are called factors of the product. Suppose a can be divisible by b, or b can be divisible by a ... a is a multiple of b, and b is a divisor (or factor) of a.

5.{x | 1 = |x| }

6. The opposite sides are equal and parallel

If it helps you, I'll answer the rest later.