Most grad schools require 1000 on GRE. It's a composite score, with two parts (like SAT). Each part has possible total of 800, mean 500, SD 100. What's the Z per section, if the 1000 is exactly...

Most grad schools require 1000 on GRE.  It's a composite score, with two parts (like SAT). Each part has possible total of 800, mean 500, SD 100.  What's the Z per section, if the 1000 is exactly equally distributed between the 2 sections?

Z = (raw score - mean)  ÷ SD

The trouble I am having is I am not sure if x is supposed to be 1000?  Or is x=600?  Maybe I am tired...I am confused.