Suppose I have the given data set of length 11 of scores:
p=[2, 5, 1 ,2 ,4 ,1 ,6, 5, 2, 2, 1]
I want to select scores 6, 5, 5, 4, 2, 2 from the data set. How many ways are there?
For the above example answer is: 6 ways
{p[1], p[2], p[4], p[5], p[7], p[8]}
{p[10], p[2], p[4], p[5], p[7], p[8]}
{p[1], p[2], p[10], p[5], p[7], p[8]}
{p[9], p[2], p[4], p[5], p[7], p[8]}
{p[1], p[2], p[9], p[5], p[7], p[8]}
{p[10], p[2], p[9], p[5], p[7], p[8]}
How can I count the ways in general?