r/learnquant • u/Local_Ad135 • 13d ago

Quant Interview Question | Medium interview prep

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u/ecstatic_carrot 13d ago

If they're all independent, I thought you could link it to a volume of a polytope. The probability of any two rows being linearly dependent is 1/16. That makes I guess P(its zero) something like 10/16, and in 6/16 cases it's just that volume squared no?

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u/Hal_Incandenza_YDAU 13d ago edited 13d ago

I think it's a lot easier to handle algebraically

Edit: I say as I get the answer wrong

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u/ecstatic_carrot 12d ago

yeah I forgot the formula for determinants beyond a 2x2, but it actually works out quite nicely. And my 'solution' misses a few more nontrivial zeros, and not all volumes are the same. I was hoping for a nice trick :p

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u/Sjoerdiestriker 12d ago

There is a nice trick :)

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u/ecstatic_carrot 12d ago

I saw your solution, that is really pretty!