131. 13306-!-item-!-187;#058&009213
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平方 is a factor of k.
(2) 7平方 is not a factor of k.
請求這題的思路,謝謝