There are 1.6x10^-3 moles of HCl and 1.5x10^-3 moles of NaOH. Therefore NaOH is the limiting reagant and after neutralisation of all the NaOH, there is still 1x10^-4 moles of HCl. This is in 50mL of solution so the concentration of HCl is 2x10^-3. And now use the pH calculation thingo to get: 2.7