In: Computer Science
Why the recursion in Pascal's Triangle is also the recursion for counting sub-sets.
If we closely look at the numbers of any row of Pascal's Triangle
For
example row 6:
The fisrt value, second value........  till sixth
value of row 6 are 
In case of counting subsets
Number of subsets of size 1 in a set of 5 values: 
Number of subsets of size 2 in a set of 5 values: 
Number of subsets of size 3 in a set of 5 values: 
Number of subsets of size 4 in a set of 5 values: 
Number of subsets of size 5 in a set of 5 values: 
Hence we can see that both the recursive program calculates nCr values. Therefore the recursive program in both the cases is same.