Question 1157603: There are six seat in a railway carriage. In how many different ways can 4 people occupy them?
My calculation : 6!x2!
and I think the answer is wrong
Answer by ikleyn(52798)   (Show Source):
You can put this solution on YOUR website! .
Your answer is wrong.
The correct answer is 6*5*4*3 = 360 ways, the product of 4 consecutive integer numbers,
starting from 6 in descending order. ANSWER
The mantra is standard for all such problems:
We can place item 1 in any of 6 positions;
item 2 in any of 5 remaining positions;
item 3 in any of 4 remaining positions;
item 4 in any of 3 remaining positions.
Solved, answered and explained.
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This problem is about PERMUTATIONS.
On Permutations, see introductory lessons
- Introduction to Permutations
- PROOF of the formula on the number of Permutations
- Problems on Permutations
- OVERVIEW of lessons on Permutations and Combinations
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Combinatorics: Combinations and permutations".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.
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