I'm taking a math quiz for a new job. Nothing like getting stuck on a test. It's nice when I'm at work, and a co-worker is available to solve it with me. The question states: There's a new order for Ampicillin 150 mg IV q 12 h. Suppose you have available Ampicillin 500 mg vials. You add 4.8 ml of Sterile water to make a final concentration of 100mg/ml. How many mls of Sterile Water must you add to your final syringe for a Final Volume of 5 mls? I think you can only add 4.8mls of the sterile water period. But it's a tricky question asking how much water to add to the final syringe. Any help is much appreciated!