Ratios in Excel Solver

[Guest]

How do I enter a ratio as a constraint in Solver? My ratio is 4:1, do I
simpy put 4:1?

 

[Bernard Liengme]

A constraint apples to the value in a cell.
If you need item-a/item-b to be in the ration 4:1
The in some cell (say D4) enter =x2/x3 where these cell ref to the items
Now make the constraint D4 = 4
Any help?

 

[Guest]

Thanks so much! I had the "B27<=" part, I just wasn't sure how to finish it.
It seems that the answer was just too simple and I wanted to confuse myself
and make it harder than it was!

 

[Dana DeLouis]

Hi. Just some thoughts. In some models, there is also the following
option.
Suppose you have [D4] = "=x2 / x3", with a constraint that D4 = 4. (x2 & x3
adjustable cells)
What you have is x2/x3 = 4. What one should try to do is make the equation
look more linear.
x2=4*x3.
But we don't want the variable on the Right side, so in D4 we write:
=x2-4*x3
and make the constraint =0.
The added benefit is that if Solver picks 0 for x3 to help determine its
next move, you won't get a Divide by 0 error in D4,and quickly stopping
Solver.
Again, just an idea. :>)