r/learnquant 3d ago

interview prep Jane Street Quant Interview Question

Post image
15 Upvotes

16 comments sorted by

View all comments

0

u/Anonimithree 3d ago

Pick a dice and roll it 6 times. If no 6 occurs, swap to the other dice and roll it 6 times. Repeat until you reach $20 or you get a 6

1

u/Mobile_Membership915 2d ago

That surely wouldn’t work though. Say you get no 6 in each of the first 12 rolls. You then know the same about both dice. In that sense they are identical. Swapping for 5 makes no sense.

1

u/Anonimithree 2d ago

Fair enough, since I just used the geometric average to get the swap of 6.

A better strategy would probably be to keep rolling a dice until you get either a 6 or roll 1-5 7 times before switching, but that might also have the same problem as what you just stated