This is the correct solution:

A: 2.5
B: 2.7
C: 12
D: =0.8/(E1*F1*G1/(1-E1)/(1-E1-F1)) expected Div
E: =0.84/A1
F: =0.84/B1
G: =0.84/C1


It matches Brave Chief's formula (oft-repeated according to the search function).

It assumes unbiased distributions, Win returns of 84% and Trifecta returns of 80%.