volume and density, three chemistry questions

1. A physician orders an injection of 0.50mg of atropine to treat a muscle condition.  It is available as  
    0.10mg/mL. How many mL would you need to fill the syringe?

2. Find the density of bone sample given that the  mass is 45.00g and the volume is 25.00mL.

3. An athlete drinks 250.0mL bottle of chocolate milk after completing a workout and it has a mass
    265.0g. What is the density of this milk?