Mixing a solution

by Bobbie
(Washington)

COuld you help with this:

Make a 10% NS soulution 1L. You have 5% and 50% NS bags only. How much of each solution will it take to make a 10$ NS 1-L bag?

Make a vancomycin IV 750 mg every bid in D5W 250mL. You have vancomycin 1 g per 20 mL. How much will you take from the 1-g vial?

I'm having trouble deciphering which is needless information and what to make into an equation. Also, this is my first week of classes.