On Jan 8, 5:43*pm, I wrote:
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.

Reduced to about 0.9 seconds with a "tedious", but obvious
optimization. Makes the program look less "elegant". Add 2-3 minutes
to the development time ;-).