Take 1mL of 1M NaCl solution, and add 9mL of water. Then take 10microL of the diluted solution and add 40microL of water. What is the dilution? And what is the final concentration of NaCl?

So I see how this is a 2:1 dilution, but I am having a hard time figuring out the final concentration of NaCl. Any help? Thanks.