Algebra Factoring Practice Test Results

Question 1
80% answer correctly
What`s the greatest common factor of 8 and 28?
2
1
8
4
Question 2
75% answer correctly
What`s the least common multiple (LCM) of 3 and 5?
30
16
15
3 and 5 have no common multiples
Question 3
65% answer correctly
Which of the following is not a composite number?
19
22
92
21