Comments on: Why do we multiply combinations?

By: kalid

kalid — Fri, 27 Jul 2018 16:23:00 +0000

Hi, check out https://betterexplained.com/articles/easy-permutations-and-combinations/ for more. Essentially you start with 8 choices, then 7, then 6, then 5 (and so on). Hope that helps!

By: Ashwin Yadav

Ashwin Yadav — Sat, 14 Jul 2018 16:21:00 +0000

thank u very much for such helpful discussion

By: Alessan Kularatnam

Alessan Kularatnam — Sun, 22 Apr 2018 11:34:00 +0000

Hi Kalid,
Great article and really appreciate it. Keep up the great work man! Just had one question.
You stated

“The numerator (n!) is the max volume assuming each of the n choices has its own dimension. The number of rearrangements of 8 people is 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1.”

How did you get this? I tried to do the square thing with the pants and shirts but still couldn’t grasp why we just multiply the numbers (8*7*6*5…) in the statement above?

Thanks in advance

By: SundaraRaman R

SundaraRaman R — Tue, 29 Aug 2017 08:26:24 +0000

> Now, let’s say the medals are identical: we’re giving a tin can to 3 out of 8 people. We need to further remove dimensions, because we have 3! = 3 * 2 * 1 = 6 redundancies for each permutation in our solution space.

This part seems unclear to me. After some thought I (think I) understand how the 3x2x1 came about, but in context it’s not obvious, and does not directly follow from the explanations before it.

I think it’ll be useful to edit in a small explanation at that point in the article.