Adding a strong acid to a buffer?

A beaker with 180 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 0.100 M . A student adds 5.80 mL of a 0.490 M solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.760.