两道简单的PREP的题, 感觉脑子昏昏的

if m is a positive odd integer between 2 and 30, then m is divisible by how many different positive prime number?

1) m is not divisible by 3

2) m is not divisible by 5

偶选的D, 答案是A

if the drama club and music club are combined, what percent of the combined membership will be male

(1)of the 16 members of the drama club, 15 are male

(2)of the 20 member of the music club, 10 are male

答案是E

请教各位了

第一题，用提干和1）可以排除质因数是2和3的可能，所以质因素只能大于等于5。这样最小两个质因素5和7相乘已经大于30了，所以最多只能有一个质因素。同理，提干和条件2能排除质因数是2和5的可能的可能，按这是最小两个质因素3和7相乘小于30，所以不知道有两个还是一个质因数。所以是A。

第二题，不知道既是drama又是music的male有多少，所以是E

谢谢清如水, 真是越做到后面脑子越昏, 当局者迷啊.