adding acid to buffered solution

A beaker with 160mL of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.1M . A student adds 6.30 mL of a 0.450M HCl solution to the beaker. How much will the pH change? The
p-Ka of acetic acid is 4.76.