Check my math

[Propping Fool]

where am I going wrong ?

I am trying to figure the prob I will place 3rd in a 6man sng. The FAQ showed me how to figure 1st and 2nd.

b = my stack
t = total tournament chips

o1 = opponent1's stack
o2 = opponent2's stack etc etc
o3
o4
o5


(b / (t - (o1 + o2)(o1+o2 / t) +
(b / (t - (o1 + o3)(o1+o3 / t) +
(b / (t - (o1 + o4)(o1+o4 / t) +
(b / (t - (o1 + o5)(o1+o5 / t) +
(b / (t - (o2 + o3)(o3+o3 / t) +
(b / (t - (o2 + o4)(o2+o4 / t) +
(b / (t - (o2 + o5)(o2+o5 / t) +
(b / (t - (o3 + o4)(o3+o4 / t) +
(b / (t - (o3 + o5)(o3+o5 / t) +
(b / (t - (o4 + o5)(o4+o5 / t) +

clearly math is not my thing
I am way off base, but I am stumped
ty