[viennagreen]

I don't think you need to run all possible sets of distributions.... in any case though--- in order to solve the question you asked:

for SNGs where tournament fee = 10% of buy-in:

f(x,y,z)= x (3.5455)+ y (1.7273)+ z (.8182) - (100 - (x+y+z))

where x= % first place, y = % second, z = % third

set f(x,y,z) to whatever ROI you want, in this case 30..

you'll see that you have a lot of answers to this function.