1. Which of the following is a group of composite numbers?
- A. 3, 8, 9
- B. 4, 9, 15
- C. None of these
- D. 4, 5, 7
Check answer and explanation
Answer: 4, 9, 15
Explanation A composite number is a positive integer that has at least one positive divisor other than 1 and itself . Let's examine the numbers: 4 : divisors are 1, 2, and 4 ( composite ) 9 : divisors are 1, 3, and 9 ( composite ) 15 : divisors are 1, 3, 5, and 15 ( composite ) Since all numbers ( 4, 9, 15 ) have divisors other than 1 and themselves, they are composite numbers. The group 4, 9, 15 consists entirely of composite numbers.