If you are looking for a solution (Not necessarily the only one) to a subset
of a group of numbers that will add up to a target number, then this can be
done quite simply with Solver.
Assuming range of numbers in A1:A30, add a set of 0s in B1:B30 and in say
B31 put
=SUMPRODUCT(A1:A30*B1:B30)
Now do Tools / Solver / Set Target Cell 'B31' to 'value of' and put in your
target number. Then, using the range selector under the 'By Changing cells'
section, select cells B1:B30 as the ones to change and hit enter which will
take you back to the first dialog box. Now hit the 'Add' button, and add
the constraint that B1:B30 must be 'bin' (Means binary as in 1 or 0, and
it's one of the dropdowns, so just hit the arrow and select 'bin') and just
hit Solve. You MUST ensure that in this example, when you add the 'bin'
constraint range, you do not inadvertantly include the formula cell B31,
else you will get an error message such as 'Binary Constraint cell reference
must include only adjustable cells'
