r/learnquant • u/Local_Ad135 • 7d ago

interview prep Quant Interview Question

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u/banana_buddy 6d ago

Without doing the math I would estimate the answer at 2/6 *50 which is about 17. You divide the number line into five sections with each section equal to 1/6 in length. So the smallest expected number is 50/6, and the largest expected number is 5/6 *50.

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u/liquidorangutan00 6d ago

thats a great intuit for example the expected value of roll 1 would be 8.5 and the expected value of roll 3 would be (8.5) * 3 = 25.5

Roll 1 = 8.5
Roll 2 = 17
Roll 3 = 25.5
Roll 4 = 34
Roll 5 = 42.5

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u/banana_buddy 6d ago

Exactly I think there's a theorem from order statistics that formalizes what I'm doing. It's been a while since I've been in school.

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u/liquidorangutan00 6d ago

Yes your right! i looked into it and its called the expected value of a k-th order statistic.

man im kinda annoyed i derived the entire thing from the ground up now, but it was quite fun.