Array formula to count unique based on value on another column

[rombo]

Sir,

Trying to find a formula which works in 2019 excel
Count unique number or person who has sold articles
Column A has person names, B has articles and C number of items sold, trying to find a formula to count unique number of persons who have sold articles

 

[Fluff]

How about

+Fluff 1.xlsm
	A	B	C	D	E
1
2
3
4	Jeff		0	0	4
5	Liam		10
6	Jeff		1
7	Liam		0
8	Niel		15
9	Linda		5
10	Bob		0
11	Linda		0
12
List

Cell Formulas
Range	Formula
E4	E4	=SUM(--(FREQUENCY(IF(C4:C11>D4,MATCH(A4:A11,A4:A11,0)),ROW(A4:A11)-ROW(A4)+1)>0))
Press CTRL+SHIFT+ENTER to enter array formulas.

 

[rombo]

Thanks a ton Sir, I missed to mention this in the earlier post, need to find unique number of persons by articles sold also

 

[Fluff]

Did the formula I proved do what you asked for?

 

[rombo]

Did the formula I proved do what you asked for?

Yes Sir, but I missed to mention another request to find number of unique person by articles sold. how many persons have sold Pen in a cell

Pen 2
(Pen was sold be two people)

 

[Fluff]

Ok, how about

+Fluff 1.xlsm
	A	B	C	D	E
1
2
3
4	Jeff	Book	0	0	2
5	Liam	Pen	10	Pen
6	Jeff	Table	1
7	Liam	Book	0
8	Niel	Pen	15
9	Linda	Pencil	5
10	Bob	Pencil	0
11	Linda	Eraser	0
List

Cell Formulas
Range	Formula
E4	E4	=SUM(--(FREQUENCY(IF((C4:C11>D4)*(B4:B11=D5),MATCH(A4:A11,A4:A11,0)),ROW(A4:A11)-ROW(A4)+1)>0))
Press CTRL+SHIFT+ENTER to enter array formulas.

 

[rombo]

Thanks Sir, the formula works .

 

[Fluff]

You're welcome & thanks for the feedback.