How many of the positive factors of 14 are not factors of 21?  Choose the correct choice from the following.
A) 4  B) 3  C) 1  D) 2  E) 0
Factors of 14 - 1, 2, 7, 14,   factors of 21- 1, 3, 7, 21,   1omparing both, we have three factors of 14 which are not factors of 21- 2,14   The answer is 1
<result>C</result>
How many of the positive factors of 14 are not factors of 21?