Between two rational numbers

1. there is no rational number
2. there is exactly one rational number
3. there are infinitely many rational numbers
4. there are only rational numbers and no irrational numbers.

Decimal representation of a rational number cannot be

1. terminating
2. non-terminating
3. non-terminating repeating
4. non-terminating non-repeating

The division of two irrational numbers is

1. a rational number
2. an irrational number
3. either a rational number or an irrational number
4. neither rational number nor irrational number