Which of the following is not a statement-

Options

A. 4 is a rational number
B. `8 gt7`
C. Please open the door
D. All prime numbers are odd.

Answer

To determine which of the given options is not a statement, we need to understand what constitutes a statement in mathematical reasoning. A statement is defined as a sentence that can be classified as either true or false.

Let's analyze each option step by step:

1. **Option 1: "4 is a rational number."**
- A rational number is defined as a number that can be expressed as the quotient of two integers (p/q) where q is not zero.
- The number 4 can be expressed as 4/1, which fits this definition.
- Therefore, this statement is true.

2. **Option 2: "8 is greater than 7."**
- This is a straightforward comparison.
- Since 8 is indeed greater than 7, this statement is also true.

3. **Option 3: "Please open the door."**
- This is a request or command, not a declarative statement.
- It does not provide information that can be classified as true or false; it simply conveys a desire or instruction.
- Hence, this is not a statement.

4. **Option 4: "All primes are odd."**
- This statement claims that every prime number is odd.
- However, the number 2 is a prime number and is even.
- Therefore, this statement is false.

Now, we summarize the findings:
- Option 1 is a statement (true).
- Option 2 is a statement (true).
- Option 3 is not a statement (it is a request).
- Option 4 is a statement (false).

Thus, the option that is not a statement is **Option 3: "Please open the door."**