Correct Answer: C
Explanation:
Arithmetic Properties of numbers
- (1) The prime factors of 15 are 3 and 5. So in
this case, k has at least 2 different positive prime
factors, but it is unknown if there are more
positive prime factors; NOT sufficient.
- (2) The prime factors of 10 are 2 and 5,
show in g that k has at least these 2 different
positive prime factors, but k might or might not
have more; NOT sufficient.
Taking (1) and (2) together, since k is divisible
by both 10 and 15, it must be divisible by their
different positive prime factors of 2, 3, and 5.
Thus k has at least 3 different positive prime
factors.
The correct answer is C;
both statements together are sufficient.