What will be the molarity of this dilution?

For my dilution, I will pipet 25.00 mL from the original 0.5000M solution and place into a 100 mL volumetric flask and fill to the mark with distilled water. What will be the molarity of this dilution after the water is added to the 100 mL mark and mixed thoroughly? Please walk me through this because I really have no idea what I am doing. D: