That depends a lot on the size of the apples.
On Earth, 750g of anything weighs 1lb 10.5oz . (In other places, it doesn't.)
6kg 750:g
750g is 1.65347 pounds.
There are 1000g in a kg so 1kg is greater than 750g(.75kg).
If you were able to collect all the dust - including the tiny air-borne articles, collect all the sawdust from the grinder, then the mass will be 750g.
You need about 1333.33 boxes of 750g cereal to make 1t
0.75 kg
750g
Depends how strong you like your coffee. I get about 65 cups from that size.
72p
0.75 kg.
at least 750g