The challenge this week is as follows: given a non-contiguous range, made up of an arbitrary number of single-column ranges, the values in each of which being either a numeric, text or null string, to generate a list, in numerical order and beginning in A2, of all numbers which occur precisely once within that range.
For example, in the below:
three numbers – 1, 2 and 9 – occur precisely once across the non-contiguous, union range defined by:
(You can download the file here.)
As usual, the formula in A2, when copied down, is to produce a blank in cells beyond the expected number of returns. What’s more, this is to be done via reference to another formula in A1, also to be derived, and whose value is equal to that expected number of returns. In this example that value is 3.
As such, the formula in A2 is to begin with:
Also note that, even though the other cells in the range C1:N12 are empty in this example, this cannot be assumed to always be the case. In fact, solvers should assume that there may be numericals within those other cells as well.
Solution next week. Best of luck!