Identify Biased Coin With Minimal Flips | Dataford Interview Questions

Your question is Identify Biased Coin With Minimal Flips. Take a moment with it on the right.

Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).

Problem

If you have two coins, one fair and one biased, how do you determine which is which with minimal flips?

The bias probability and acceptable probability of misidentification are not specified, so first determine whether a finite, guaranteed solution exists. Then describe an optimal sequential procedure under explicitly stated assumptions, including how the stopping rule depends on the bias and error tolerance.

Requirements:

Distinguish certainty from probabilistic identification.
Explain why the problem is under-specified as written.
Give a sequential likelihood-ratio approach when the biased coin's head probability and error tolerance are known.
State the assumptions behind the procedure.

Your question is Identify Biased Coin With Minimal Flips. Take a moment with it on the right.

Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).

If you have two coins, one fair and one biased, how do you determine which is which with minimal flips?

Requirements:

Distinguish certainty from probabilistic identification.
Explain why the problem is under-specified as written.
Give a sequential likelihood-ratio approach when the biased coin's head probability and error tolerance are known.
State the assumptions behind the procedure.