If 10.0 mL of blood plasma has a mass of 10.279 g and contains 0.870 g of protein, what is the mass/mass percent concentration of protein in the blood plasma

Mass/mass percent concentration means the mass of the solute/mass of the solution times 100. You know both the mass of the solute (0.870 g protein) and the mass of the solution (10.279 g solution). So divide and multiply your result by 100.  (0.870 / 10.279 * 100)

Explanation:

age range would be the answer