You are doing a red blood count with a standard dilution of 1/200. The area counted is 10 red squares in a Neubauer chamber. Under these conditions, what is the factor that would be used to determine the number of cells in the undiluted blood?

I have never used a Neubauer chamber. I looked through some of the google articles and found three, all of which differed in size and number of counting squares as well as volumes of each counting square. Since they weren't standard the articles didn't make sense to me.