If we think of the picture nails as slots
we have
___ ___ ___ ___ ___ ___ ___
1 2 3 4 5 6 7
There will be two blank slots.
There are 5 distinct paintings and 7 picture nails. In how many ways can the 5 paintings be hung from the 7 picture nails.?
2019-11-16 5:38 am
回答 (1)
2019-11-16 7:30 am
7P5 = 7 * 6 * 5 * 4 * 3
= 2,520
If you still aren't sure how to get that answer, think of each painting.
There are 7 choices of where to hang the first painting.
There are 6 choices of where to hang the second painting.
There are 5 choices of where to hang the third painting.
There are 4 choices of where to hang the fourth painting.
There are 3 choices of where to hang the fifth painting.
So the total ways would be:
7 * 6 * 5 * 4 * 3
= 2,520 ways
= 2,520
If you still aren't sure how to get that answer, think of each painting.
There are 7 choices of where to hang the first painting.
There are 6 choices of where to hang the second painting.
There are 5 choices of where to hang the third painting.
There are 4 choices of where to hang the fourth painting.
There are 3 choices of where to hang the fifth painting.
So the total ways would be:
7 * 6 * 5 * 4 * 3
= 2,520 ways
收錄日期: 2021-04-24 07:42:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20191115213806AA0AfUl