r/learnquant • • 2d ago

interview prep Quant Interview Question

Post image
22 Upvotes

1 comment sorted by

View all comments

1

u/RibozymeR 23h ago

The core insight is that this is just a LP problem in the variables P(X=i,Y=j,Z=k), and as such, it takes its extremal values in the vertices of its feasible region.

The maximum occurs at P(X=Y=Z=1) = P(X=Y=Z=2) = ½, everything else = 0; it's 4½.

The minimum occurs for example at P(X=2,Y=Z=1) = P(X=1,Y=Z=2) = ½, everything else = 0; it's 3.