Example 7 - Evaluate n!/r!(n - r)! when n = 5, r = 2 - Factorial

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  1. Chapter 7 Class 11 Permutations and Combinations
  2. Serial order wise

Transcript

Example 7 Evaluate n!/r!(n r)! when n = 5, r = 2. !/ !( )! Putting n = 5, r = 2 5!/2!(5 2)! = 5!/(2! 3!) = (5 4 3!)/(2! 3!) = (5 4 )/(2 1 ) = 20/2 = 10

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Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.