From 1 liter of a 1.0 M stock of NaCl make 15 ml of a 0.25 M solution

I need help with this problem, or maybe someone can just guide me in the right direction... I would my answer be in g/L? I'm confused, but I would really appreciate your help! :)

(15 ml) x (0.25 M) / (1.0 M) = 3.75 ml

So take 3.75 ml of the stock solution, then add enough water to make exactly 15 ml of diluted solution. (Supposing additive volumes, you would add 15 - 3.75 = 11.25 ml of water.)