

1. 
Which of the following numbers is prime? 


A. 
9 
B. 
5 


C. 
15 
D. 
1 


Hint 


2. 
Which of the following numbers is composite? 


A. 
9 
B. 
31 


C. 
23 
D. 
1 


Hint 


3. 
What are the prime factors of 400? 


A. 
4, 10, 10 
B. 
2, 4, 5 


C. 
2, 200 
D. 
2, 5 


Hint 


4. 
What are the prime factors of 810? 


A. 
2, 5, 9 
B. 
3, 4, 5 


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


Hint 


5. 
Factor 8x^{2}. 


A. 
2 · 2 · 2 · x · x 
B. 
2 · 2 · 2 · x 


C. 
2 · 4 · x · x 
D. 
8 · x 


Hint 


