I agree that modern computer exection time is quite fast, but for me the real
issue would be the time required to program and validate a routine that would
run through all the combinations. That is the beauty of the generating
function approach.

Jerry

"joeu2004" wrote:

On Jan 8, 9:39 am, Jerry W. Lewis wrote:
There are 352716=COMBIN(21,10) different ways to get 10 successes from
21 trials. You could enumerate them and sum the probability of each.
[....]
Of course this approach would be exceptionally tedious and time consuming.

Only took less than 63 milliseconds for a VBA UDF to run through all
combinations. Took less than 2.4 seconds for the UDF to sum the
probability of exactly 10 successes over all combinations. Of course,
YMMV depending on the speed of your system. Took 5-10 minutes to
write the VBA UDF.

To the OP (mk9999999): Is this a programming assignment or an
assignment in statistics or probability?