Compute probability at least one user uses feature
Company: Coinbase
Role: Data Scientist
Category: Statistics & Math
Difficulty: easy
Interview Round: Technical Screen
## Problem
Assume there are \(n\) users. Each user independently uses a certain feature with probability \(p\).
1) What is the probability that **at least one** user uses the feature?
2) What is the probability that a **particular** user (say user 1) used the feature **given that at least one user used it**?
3) (Optional extension) What is the expected number of users who used the feature **given that at least one user used it**?
Quick Answer: This question evaluates understanding of basic probability concepts including independent Bernoulli trials, complementary probability, conditional probability, and conditional expectation.