

1. 
Which of the following numbers is prime? 


A. 
15 
B. 
9 


C. 
5 
D. 
1 


Hint 


2. 
Which of the following numbers is composite? 


A. 
31 
B. 
9 


C. 
1 
D. 
23 


Hint 


3. 
Which of the following numbers is prime? 


A. 
57 
B. 
63 


C. 
75 
D. 
43 


Hint 


4. 
What are the prime factors of 810? 


A. 
3, 5 
B. 
2, 5, 9 


C. 
3, 4, 5 
D. 
2, 3, 5 


Hint 


5. 
Write the prime factorization of 810. 


A. 
2 × 5 × 9^{2} 
B. 
3^{2} × 4 × 5 


C. 
2 × 3^{4} × 5 
D. 
2 ×3 × 5 


Hint 


