SUMIFS with WEEKNUM formula

Hello,

I want to get a sum result by week. In the actual sheet, I am not allowed to add another colum for week but have to provide data on weekly basis.

Data Example : https://docs.google.com/spreadsheets...it?usp=sharing

7/3/2018 Mamun 10
7/3/2018 Mamun 10
7/23/2018 Mamun 2000
7/23/2018
7/23/2018 Rahim 2000
7/27/2018 Mamun 2000
7/27/2018 Mamun 2000

Column A has Date, B has performer name and C has output unit number.
Using - =ARRAYFORMULA(sumif(ISOWEEKNUM(A6:A21),A4,C6:C21)) formula only can count total amount based on week but need some additional count. it will count data by name filtering. like on week 30, Mamun produce 6000 and Rahim produce 2000.

Hi Glenn Kennedy,

I am sorry. I was trying to working with MS office. I asked for help from a friend and he shared me through Google Excel. I thought formula in both formats will be the same.
Here is the actual file.
In the assist tab, I need to use a formula in D column.

Thank you
Rinko

Hi Glenn,

Yes, you are right and thank you so much for your help.

Best,
Rinko.