139. Solving a chemistry problem

3. To 10.00 ml of hydrochloric acid, an excess of a mixture of iodide (KI) and potassium iodate (KIO3) is added. The released iodine was titrated using 15.70 ml of sodium thiosulfate, 1.00 ml of which is equivalent to 0.90 ml of a potassium dichromate solution with a concentration of 0.05 mol-equiv / L. Calculate the molar concentration equivalent (normality) of the acid solution.