CSE 21
Math for Algorithms

RQ8 Q3: Burrito Shop

A burrito shop messes up your order with an independent probability of 1/4 every time you visit. Let X be a random variable representing the total number of times they mess up your order across 16 separate visits. Thus X can be any integer from 0 to 16. What is var(X)?

Solution: var(X) = 3. There are two main ways to arrive at this result.