If a number 105 divides into n with no remainder, which of the following must be a factor of n?  Pick:
A) 2 B) 4 C) 6 D) 7 E) 11
105 / n = k (with k an integer)   (7)(5)(3) / n = k   n must have a 7 in his prime factorization to divide 105 without remainder.   answer 7
<result>D</result>
If a number 105 divides into n with no remainder, which of the following must be a factor of n?