Using a pipet, 10 mL of a 0.1005 M HCl solution was paced in a 50 mL volumetric flask and the flask was filled to the mark with water. What is the concentration of the new solution?

V1C1 = V2C2 where V1 is the volume of the initial solution (the volume of the first volumetric flask), C1 is the concentration of the first solution. V2 is the volume of the second volumetric flask, C2 is the concentration of the second solution (diluted solution).