The positive integer k has exactly two positive prime factors, 3 and 7. If k has a total of 6 positive factors, including 1 and k, what is the value of k?
(1) 3^2 is a factor of k.
(2) 7^2 is NOT a factor of k.

OA is D

Total number of factors of an integer can be obtained by breaking down the integer in to its prime factors, adding 1 to each of the powers to which the individual prime factors are raised and multiplying them together

Eg: 6 = (3^1) * (2^1)

Total # factors of 6 = (1+1)*(1+1)
= 4

4 factors namely 1,2,3,6

Coming to the problem since k has 6 factors including 1 and k and 3 and 7 are its only prime factors k can either be

(3^2) *(7^1) => (2+1) (1+1) = 6 factors

or

(3^1) * (7^2) => (1+1) (2+1) = 6 factors

Stmt I

3^2 is a factor of k so k is 3^2 * 7^1

SUFF

Stmt II

7^2 is not a factor of k
so k again = 3^2 * 7^1

SUFF

D

Hope this helps!

Regards,
CR