A beaker with 165 of an acetic acid buffer with a pH of 5.00 is sitting on a benchtop?

A beaker with 165 mL 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 0.1 M. A student adds 4.40 mL of a 0.400 M HCl solution to the beaker. How much will the pH change? The pK_a of acetic acid is 4.76.