Which one is not a statement `:`
(a) The sun is a star
( b) 8 is less than 5
(c ) Mathematics is fun
( d ) Moon is a heavenly body.

Answer

To determine which option is not a statement, we need to analyze each of the given sentences. A statement is a declarative sentence that is either true or false, but not both.

1. **Option (a): The sun is a star.**
- This is a factual statement. It can be verified and is true. Therefore, it is a statement.

2. **Option (b): 8 is less than 5.**
- This is also a factual statement. However, it is false because 8 is not less than 5. Regardless of its truth value, it is still a statement.

3. **Option (c): Mathematics is fun.**
- This sentence expresses a personal opinion or subjective belief. It cannot be universally classified as true or false because it depends on individual perspectives. Therefore, it is not a statement.

4. **Option (d): The moon is a heavenly body.**
- This is a factual statement. It can be verified and is true. Therefore, it is a statement.

After analyzing all the options, we conclude that the sentence that is not a statement is:

**Final Answer: (c) Mathematics is fun.**