Question

Which is not a valid range? a1:a3, b1:b3 a1:a9 a1:f9 a1:f1?

Answer 1

a1:f9 is not an valid range because it has neither a row nor a column in common. This contrasts with a1:a3, b1:b3, and a1:a9 which each have a row in common, as well as with a1:f1, which has a column in common. In general, to make a valid range coordinates must be specified that allow a single row or column of cells to be specified.