Jane Street–styleTrader InternQuant Trader InternQuestion #298
You repeatedly roll a fair six-sided die. After each roll, you add the result to your cumulative score. At any point, you may choose to stop the game and keep your current score. However, if your total score ever becomes a perfect square, you immediately lose and receive zero points. What is the optimal strategy to maximize your expected score?
Build Your Approach
State the assumptions, try a simple case, then work toward a general solution. Check the result and explain how it changes if an assumption changes.
Try the free diagnostic with worked solutions →Get Free Interview Prep Resources
More Jane Street–Style Trader Intern Questions
In a group of 10 people standing in a circle, how many handshakes occur if each person shakes hands with every other person exactly once?Find the smallest positive integer x such that x raised to the power x (x^x) contains the digits '2016' consecutively. Determine a range [n, 2n] that contains this x. Additionally, specify how much you would bet on your choice and your level of confidence.How many throws of a fair 6-sided die are expected until each number appears at least twice?If copying, pasting, and typing a letter each take one second, what is the fastest way to reach at least 200 letters written?You roll a 4-sided die and sequentially accumulate the total score from each roll. What is the expected value of the first total that exceeds 100? Follow-up: What if you start at 96 instead of 0?
Practice the Reasoning Behind the Answer
Bring your target roles and interview timeline to a free quant consult. Discuss your preparation priorities and how Quant Blueprint’s lessons, practice and mock interviews can help.
Book a Free Quant ConsultYour goals · your preparation · your next steps