[討論]GMATPrep 更好ㄉ解法?

[unwindedson]

m, p, q, r are integers.
2<m<p, p=mq+r, 且 r is not zero,
r>1?
(1)the greatest common factor of m and p is 2
(2)the least common multiple of m and p is 30
答案A
有人的解法比我的更直觀，更快嗎?
any idea is welcomed

(1):p=mq+r -> r=1, 2, 3, 4.....etc
mq is even, 又p is even -> r is not '1' -> r>1
充分
(2):我是找數字代入的，any better idea?
15=2x7+1, 15=6x2+3