How to calculate molarity of HC?

how to calculate molarity of HCl when given the following data for the following separate titrations. mL Molarity mL Molarity HCl HCl NaOH NaOH a) 40.13 ? 37.70 0.728 b) 19.00 ? 33.66 0.306 c) 27.25 ? 18.00 0.555 Please show me how to set each problem up so that will understand. Thank You