Example 10 - Chapter 7 Class 11 Permutations and Combinations
Last updated at May 29, 2018 by Teachoo
Transcript
Example 10(Method 1) How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed? n = Numbers from 1 to 9 = 9 r = 4 Required 4 digit number = 9P4 = 9!/((9 4)!) = 9!/5! = (9 8 7 6 5!)/5! = 3024 Example 10(Method 2) How many 4-digit numbers can be formed by using the digits 1 to 9 if repetition of digits is not allowed? Let the 4 digit number be Number of 4 digit numbers which can be formed = 9 8 7 6 = 3024
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Example 10 You are here
Example 11
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Example 13 Important
Example 14
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Example 16 Important
Example 17
Example 18
Example 19 Important
Example 20
Example 21
Example 22
Example 23 Important
Example 24
Chapter 7 Class 11 Permutations and Combinations
Serial order wise
About the Author
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 8 years. He provides courses for Maths and Science at Teachoo. You can check his NCERT Solutions from Class 6 to 12.