find parts of a total
 

I have 60 random numbers in a column of a spreadsheet. I know that 10 of
these numbers make up the sub total of a specific amount. If I know the
amount of the subtotal and know that 10 numbers sum to the sub total, how can
I have Excel extract or tell me which of the 60 random numbers sum to my sub
total?

Thanks, Jim

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
often 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 Contsraint cell reference
must include only adjustable cells'

Won't do any more than single solution, but for a Finance Dept that will
often
suffice in this context.

The following link, will give you a helpful tutorial at
http://www.solver.com/stepbystep.htm
and which walks you through an interesting scenario and explains what you
can do with the tool.

If you are going to look for more than one target number in the data, then
with
that formula in say B31, in B32 type the target number, and in B33 put
=B32-B31.
Now have Solver solve B33 = to 0 with the same constraints. Saves having to
change any values in Solver that way, just type what you want in B32.

Looks quite neat too if you format B1:B30 to a white Font and then use
conditional formatting to highlight values in Col A where Val in Col B = 1

--
Regards
Ken....................... Microsoft MVP - Excel
Sys Spec - Win XP Pro / XL 97/00/02/03

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It's easier to beg forgiveness than ask permission :-)
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"Jim" wrote in message
...
I have 60 random numbers in a column of a spreadsheet. I know that 10 of
these numbers make up the sub total of a specific amount. If I know the
amount of the subtotal and know that 10 numbers sum to the sub total, how
can
I have Excel extract or tell me which of the 60 random numbers sum to my
sub
total?

Thanks, Jim