A spreadsheet interview often starts with ordinary work: add a column, count matching records, return a value for an ID, or explain a boundary. Read the requested output before selecting a function. A count of rows is different from a sum of hours, and an average can include a genuine zero.
These questions use a fictional support export. Each task starts from its own copy, so you can work in any order without relying on an earlier answer. Write a formula that would still work if the underlying hours changed. A number copied from a calculator doesn't show how you reached it. When a task gives an inclusive threshold, include the value at that threshold.