请教gwd 一道数学题

is the integer n odd?

(1)n is divisible by 3

(2)2n is divisible by twice as many positive integers as n

key :B

这道题在prep模拟时就遇到过 不明白到底什么意思

2.A certain characteristic in a large population has a distribution that is symmetric about the mean m .If 68%of the distribution lies within one standard deviation d of the mean , what percent of the distribution is less than m+d? 这个题什么意思 纯粹没看懂  谢谢了