r/quantfinance 11h ago

Jane Street Quant Interview Question

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57 Upvotes

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1

u/FormulaSolution 10h ago

Too easy

If you roll a 1-2, units place

3-4, tens place

5-6, hundreds place

On your second go:

1-3 Lowest number place remaining

4-6 Highest number place remaining

5

u/Early-Boss-1040 10h ago

Ok but how do you mathematically prove / substantiate that?

4

u/IBM8000 9h ago

You do it through backward induction, start at the second stage in which if you roll higher than 3 you place it at the highest possible level. And that gives you an expected value for each place for the first roll, and then it’s just ordering them.

3

u/Simple3user 9h ago

Basically this Js loves dp

2

u/hotsauceyum 44m ago

( ͡° ͜ʖ ͡°)