Algebra Factoring Practice Test Results

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