Why Division is Not Closed

Q.

What is the multiplicative inverse of 0?

1. 1

2. 0

3. -1

4. Does not exist.

Q.

The reciprocal of ______ does not exist.

Q. Under which operator is the set of rational numbers not closed?

1. Addition
2. Subtraction
3. Multiplication
4. Division

Q. The rational numbers are not closed under .

1. addition
2. subtraction
3. multiplication
4. division