How to compare data in two columns of different sheets to find duplicates in Excel

Question

I have two excel Sheets SheetA and SheetB . Both sheets have thousands values. Some values are same in a Column "Numbers" in SheetA and in a column "No." in SheetB . Now I want to make an extra column in SheetA with name "Duplicate" which would have only duplicated or repeated values of SheetA column "Numbers" and SheetB column "No." How is it possible...? Images are given below

Thanks

Answer 1

Paste the below formula in your F2 cell of SheetA. Then copy it to other cells.

=IF(AND(COUNTIF(B:B,B2)>1, COUNTIF(SheetB!C:C,B2)>1),B2,"")