Q1. Describe the Gambler's Ruin problem. Explain how you can find out the duration of a walk, both in the case of unbiased walk and biased walk.
- Gambler's Ruin models two players with fixed stakes until one runs out of capital.
- The problem is a random walk with two absorbing barriers at 0 and total capital N.
- Duration of a walk is the expected number of games until one player is ruined.
- For an unbiased walk (p=q=0.5), expected duration `E_i = i(N-i)`.
Answer: The Gambler's Ruin problem is a classical concept in probability theory, particularly relevant in actuarial economics for understanding risk and duration of financial processes. It models a scenario where two players, say Player A and Player B, engage in a series of games. In each game, one player wins a fixed stake from the other, and the game continues until one player runs out of money, i.e., is 'ruined'. This problem can be conceptualized as a random walk on a line segment with two absorbin...