Q1. Given two tables, user and friends, find list of all friends. Q2. What would be eventual consistency in case of a banking application, another application which requires data to be updated in 10 milli sec. Q3. Given an array of arrays, the sub array consists of child_id and parent_id e.g. [ [3, 5], [3, 6], [1, 5], [1, 6]] write a function to find if two ids have common parent or not.

They asked me how to solve several hypothetical problems.