Composite numbers and
prime factors
Which set is not made up only of prime
numbers? Circle the correct answer.
a {1, 2, 3, 5, 7, 11, 13, 17.}
b {13, 17, 19, 23, 29, 31, 37, 41.}
c{17, 19, 23, 29, 31, 37, 41, 43.}
d {31, 37, 41, 43, 47, 53, 59, 61, 67.}
nr circle the correct answers.​