=if(sumproduct(--(Sheet1!$A$1:$A$100=A2),--(Sheet1!$B$1:$B$100)=B2)=0,"N","Y")
Enter that in Sheet2!C2 and copy it down to fill out your table on Sheet2.
The 100s can be changed to the final row of your data on Sheet1.

"PJS" wrote:

Hello,
I am running into a problem and I am not sure which function to use.
Suppose I have a worksheet1 with of data i.e. the person and the brand of
cars they own.

Person Car
A BMW
A Ford
B GM
B Mercedes
B Porsche
C Honda
D Toyota
D Lexus

Is it possible to create a second worksheet ~ say worksheet 2 and depending
on the data from worksheet 1, it would fill out Y, N

Person Car Own (Y/N)
A BMW Y
A Ford Y
A GM N
A Mercedes N
A Porsche N
A Honda N
A Toyota N
A Lexus N

Thank you for your time!

PJS