"LF.TEN" wrote:
'joeu2004[_2_ Wrote:
And do you want "about" 80% (which might be less); or
do you want "no less than" 80%?
[....]
You might start with the VBA code mentioned at
http://www.sulprobil.com/html/accoun...e_problem.html.
[....]
Actually I want to know the fewest items that sum to about 80%.

The take-away from my previous posting is: this is a very difficult nut to
crack in general, and no simple Excel formula or single function is likely
to produce the desired result except by accident or by coincidence.

It requires an iterative algorithm, best implemented in VBA, IMHO. Even so,
I believe it is a very complex algorithm when designed correctly.

Think about it! Imagine that you have an empty box and a set of
oddly-shaped malleable shapes of varying size. You might start by picking
the largest ones (assuming they fit at all); but eventually you might need
to pick some of the smallest ones to fill the remaining space as best as
possible. Alternatively, you might find a set of shapes that overflows the
box, but by less than the unfilled space with the first set.

If you did this manually, there would be a lot of trial-and-error with a lot
of intuitive thinking going into the selection criteria. No different for a
computer algorithm.

Again, start with the aforementioned VBA code. It might do what you want as
is; if not, it might provide a good starting point for the desired
algorithm.

Good luck!