In Barcelona during a certain week the average daily rainfall from Sunday to Friday exceeded the average from Monday to Saturday by 16.667%.
The week was on the average just as wet as Sunday.
What was the fall on Saturday?
Let's say that the rain on Sunday through Friday = y per day, and the rain on Saturday was x.
Then 7y/(6y + x) = 7/6
Solving x = 0, so it did not rain on Saturday.
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More precisely,
7y/(6y+x) = 1.16667
This implies x is slightly negative. Evaporation, maybe?
I think it is roundoff, not runoff.
How do we treat evaporation? (spoiler)
