Hi. For this small problem, note that you do not have any constraints.
Therefore, there are an infinite number of solutions.

One quick solution with 3 equal values (100 gpm) is to assign a penalty
weight for each station. For example, assign a penalty of 1 to #1, 2 to
#2, ..etc

Change the logic to "Minimize the penalty" with the constraint that
Sumproduct(GPM, Percentage) = 175.

Now, you will fill station 1 first, then start using station 2, etc.

Make sure the option for "assume non-negative" is selected. )

The "General" technique for selecting "2 out of 3" (or whatever) is to
assign 3 cells to hold "Binary" cells (0 or 1 in Solver)

Target:
Sumproduct(GPM, Percentage, Binary) = 175
Subject to:
Binary cells = Bin (Binary)
Sum(Binary) = 2

(I like to use <= 2.1 to account for any rounding issues)

For each, one needs to add the constraint that Percentages <= 1

Good luck.
= = =
HTH
Dana DeLouis



Soccer boy wrote:
I am currently trying to use Solver to help optimize some water pump usage.
I have three locations where these pumps are located. If the water demand
can be met by two sites alone i would prefer to only use those two sites not
the three.
For instance
Site A - 100gpm
Site B - 100 gpm
Site C - 100gpm
I need 175 gpm so solver would tell me 100% use on Site A, 75% use on Site B
and 0% on site C.
Currently Solver is giving me Site A =58.33%, B=58.33%, and C=58.33%
So is there i way i can do this?