Other uses of 中

Question

What’s the difference between 办法 and 办法中？

I found the latter in:

他告诉我三百六十种办法中的每一种。

But I cannot make sense of why 中 is in this sentence.

I read a few answers related to 中 here but I’m not quite sure “within” or “in” is the right answer here.

Answer 1

中 can also mean "among" (short for 之中)

三百六十种办法[中] = [among] the 360 ways

Another example:

化学元素[中]，鉄是最稳定的 = [Among] the chemical elements, iron is the most stable

在鸡群[中]，一只白鹤自然十分突出 = [In/ among] the flock of chickens, a white crane is naturally very prominent

Answer 2

You can also use 之中.

化學元素"之中"，鉄是最稳定的 and 化學元素"中"，鉄是最稳定的 have the same meaning.