From the archive
Day 47
Saturday, 19 September 2026
Bill only the memberships that are actually still active
SUMIF and COUNTIFS only touch the rows that satisfy every condition you give them, so a cancelled or paused membership can sit in the sheet without ever counting toward the active numbers.
Task:
You run billing for a neighbourhood gym. The membership sheet below lists every signup on the books, whatever its current status, across three plans. In D10, count how many Premium memberships are actually Active. In D11, total the monthly revenue coming in from every Active membership, of any plan. In D12, find the average monthly fee paid by Active Family plan members.
The daily challenge is part of Pro
A new exercise every morning, plus every day that came before it — a back catalogue that grows by one a day, whether or not you were here for it.
Recent days
The last 14 days. Today's challenge is free while your streak is alive; Pro opens every past day too.
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