citadel | | Interview Experience
Interview Date: Not specified
Result: Not specified
Difficulty: Not specified
Interview Process
The interview consisted of multiple rounds focusing on probability and statistics questions. The format was primarily problem-solving with a focus on expected values and scenarios involving random events.
Technical Questions
- Frog jump from ground to rock to grass: Ground to rock success probability = 1/3, rock to grass success probability = 1/4. Calculate the expected number of jumps to escape.
- Two teams play a tournament until one team has won 3 total games (best of 5). Calculate the expected number of games played.
- Drawing socks: There are 10 socks (5 red and 5 white). What is the probability of making two pairs after drawing 4 socks?
- Hair color problem: 4 people with red hair and 8 people with black hair. Calculate the expected number of adjacent pairs of people with the same color hair.
- Bus problem: Red buses are late 3/4 of the time, blue buses are late 1/3 of the time. If a person randomly gets on a bus and is late, and the probability of riding a red bus is 1/2, what is the ratio of red to blue buses?
- Tourist problem: Three tourists visit one of three islands, chosen independently and randomly. Calculate the expected median number of tourists across the three islands.
- Neighborhood walking time: In a neighborhood of 25 people, all take a walk with a mean of 80 minutes and a standard deviation of 10 minutes. What is the standard deviation of the entire neighborhood’s walk?
Tips & Insights
Focus on understanding probability concepts and practicing problem-solving under time constraints. Familiarity with expected values and statistical distributions is crucial for success in these types of interviews.