Composite Number Identification: Select the Non-Prime Integer

To solve this problem, we will follow these detailed steps:

• Step 1: Understand the definitions: A composite number has more than two divisors. A prime number has exactly two divisors.
• Step 2: Examine each choice to determine its type:
• $9$: Check divisibility by numbers other than 1 and itself. $9$ is divisible by 3, as $9 \div 3 = 3$. Thus, 9 is composite.
• $7$: Check divisibility. Only divides evenly by 1 and 7. Thus, 7 is prime.
• $3$: Check divisibility. Only divides evenly by 1 and 3. Thus, 3 is prime.
• $5$: Check divisibility. Only divides evenly by 1 and 5. Thus, 5 is prime.
• Step 3: Conclude which number is composite based on the divisor check:
• Since 9 is the only number with more than two divisors (1, 3, and 9), it is the composite number.

Therefore, the solution to the problem is $9$.