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8?B?TmF2eSBTdHVkZW50?= <Navy says...
If I constrain a reference cell to binary (i.e. =binary), solver returns
fractional answers. I even added integer constraints to the cells and still
got fractional answers.

Did it solve the problem? Or did it pop up with an error about how it
cannot find a solution?

Solver uses something called the branch-and-bound algorithm. The
consequence of this approach is that only when it reaches a solution
are the binary/integer constraints honored. So, if it doesn't reach a
solution, the values can be non-integer.

Even when it reaches a solution, what is considered an integer value is
often within the realm of "close enough." In other words, it might
leave a result at 0.9999999 instead of exactly 1. I believe -- but am
not sure -- that this is controlled by the 'Precision' value in the
Solver options dialog box.

--
Regards,

Tushar Mehta
www.tushar-mehta.com
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