Factory overhead confirmation

Hi All

How do you confirm factory overhead if material has co-product?

Scenario:

material x (as main product) = 30,000 qty

material y (as co product) = 69,000 qty

What will be the entry in factory overhead field in CO11N? Is it the total qty which is 99,300? Or total qty divided by 2? Or we'll get the assigned apportionment/ratio for this?

Thank you

Jesielle