How many pairs (n, n+1) have one or more prime factors common, where n is an integer and 2 ≤ n ≤9 ? Choose the correct choice:
A) 0
B) 1
C) 2
D) 3
E) 4
n and n+1 are consecutive integers.   Two consecutive integers are co-prime, which means that they don't share ANY common factor but 1. For example 20 and 21 are consecutive integers, thus only common factor they share is 1.   0nswer: 0.
<result>A</result>
How many pairs (n, n+1) have one or more prime factors common, where n is an integer and 2 ≤ n ≤9 ?