Permutation, Combination & Binomial Expansion are very important concept and will be useful in further studies as well
Permutation means arrangement and is used to find out, how many was we can arrange things or people or items.
Combination means selection and it used to find out, how many was can selection be done.
For eg : Selecting 11 players out of 16 players for a cricket match is Combination, while the batting order is Permutation
Binomial Expansion is used in advance probability concepts.