Serial dilutions help

Feb 2015
Hi there - please help!

If I have 10mls of stock solution at 10-3 M (I assume this means 10-3 moles per litre). How do I create 1ml of 10-4M? and then 1ml 3x10-4M solutions?

Do I just take 1 ml of stock solution and add this to 9 mls of distilled water for 10-4? And then take 3 mls of this and add 7mls of water for 3x10-4?
May 2010

I agree with part 1.For part 2 I would take 3 ml of 10^-3M and dilute to 30 ml with water to get 3* 10^-4 M