(1) m is not divisible by 3. 5, 7, 11, 13, 17, 19, 23, 25 Each one only has one prime number as its factor. So condition 1 is sufficient.
(2) m is not divisible by 5. 3, 7, 9, 11, 13, 17, 19, 21, 23, 27 21= 3 * 7. So 21 has two prime numbers as factors while the rest of the numbers only have one prime number as their factor. So condition 2 is not sufficient.
(1) m is not divisible by 3. 5, 7, 11, 13, 17, 19, 23, 25 Each one only has one prime number as its factor. So condition 1 is sufficient.
(2) m is not divisible by 5. 3, 7, 9, 11, 13, 17, 19, 21, 23, 27
21= 3 * 7. So 21 has two prime numbers as factors while the rest of the numbers only have one prime number as their factor. So condition 2 is not sufficient.
京公网安备11010202008513号 京ICP证101109号 京ICP备12012021号
发表于 2010-12-14 04:20:01
收藏
收藏
楼主