Formulas For Combination

December 15, 2020

Formulas for Combination

Formula of Combination used for calculating the number of ways of selecting the items

Formula of Combination , ^nC_r = \frac{n!}{(n-r)! r! }

Combination formula

Combination Formulas

  • Number of all combinations of n things, taken r at a time, is given by

nCr = \frac{n!}{(n-r)! r! } n!/(r!) (n-r)!

  • n-combinations from a set with n elements (without repetition)

nCr = \frac{n!}{(n-r)! r! }

  • n-combinations from a set with n elements (with repetition)

r + n – 1Cr = C (n, r)

Points to remember in Combination Formulas

  • nCn = 1
  • nC0 = 1
  • nCr= nC(n – r)
  • nC0 + nC1+ nC2+ nC3+ ……………+ nCn = 2n

 

Read Also – Tips and tricks of Combination