Which formula should i use to display duplicates in another row?

[oqs]

Hello everybody,

I received an excel test from a possible employer but i can't figure out this one problem. I would appreciate any help or suggestions. I am a novice user of excel.

Thank you!\View attachment problema.xlsx

 

[NBVC]

Hint: use a counting formula that uses criteria to determine number of matches, range starts from beginning to current row...