How to Calculate Combinations ?
Important Note : To calculate combinations,
- First you should calculate all the equivalent permutations.
- Later you should correct this list by cutting out duplicates / repetitions.
Now lets have a look at the mathematical formula for Combinations..
|nCr =||n!||=||n(n – 1)(n – 2) … … r||.|
|(r!)(n – r!)||r!|
n above case n is 4 and r is 3, so
nCr = C(n,r) = 4
That’s all for now friends. In our next post we shall discuss some practice problems on Permutations and Combinations.