3.

Is the following statement a good definition? Why?

An integer is divisible by 100 if and only if its last two digits are zeros.

Yes, it is. When the definition is separated into two conditional statements, one of the statements is true.

No, it is not. When the definition is separated into two conditional statements, one of the statements is false.

No, it is not. When the definition is separated into two conditional statements, both of the statements are false.

Yes, it is. When the definition is separated into two conditional statements, both of the statements are true.

3 answers

Yes, it is. When the definition is separated into two conditional statements, both of the statements are true. This definition clearly states the condition under which an integer is divisible by 100, making it a good definition.
4.
Is the following statement a good definition? Why?

A segment is part of a line.

Yes, it is. All segments are parts of lines.

No, it is not. The statement is too short to be a good definition.

No, it is not. The statement is not precise. A ray or a point could be part of a line.

Yes, it is. The statement is precise and reversible.
No, it is not. The statement is not precise. A ray or a point could be part of a line. A segment is more specifically a portion of the line between two points. So the statement is not accurate as a definition of a segment.