Online Course Discussion Forum

II-A Math Combinatorics Lecture One Question #1.21

 
 
WuZeyin的头像
II-A Math Combinatorics Lecture One Question #1.21
WuZeyin - 2021年09月1日 Wednesday 06:53
 

The answer wrote 768, but why is it *3*2 at the end? There are only five possibilities with a jacket and/or a hat: h1, h2, j, h1+j, or h2+j, where h1 & h2 represent the two hats and j represents the only jacket. Therefore, why isn't it *(3+2)?

 
hehansen的头像
Re: II-A Math Combinatorics Lecture One Question #1.21
hehansen - 2021年09月3日 Friday 17:25
 

I can't see the problem, but can you have neither jacket nor hat?


If I am correct, then this is what 3 * 2 means. The 3 comes from no hat, h1, or h2. The 3 comes from no jacket or j1.