Jane Street

Interview Question

Intern Interview
Jane Street

a) What is the expected value of a die? b) Suppose you play a game where you receive a dollar amount equivalent to the number of dots that show up on a die. You roll once; if you don't like the result, you may reroll, but you must keep the second roll. What is the fair value of this game? c) Same as (b), but now you may reroll up to twice.

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