I believe this question has additional detail which stated that during the 1st half, his speed was 2.01 m/s. From this we can calculate his speed during the second half, v2, using the formula:
v_ave = (v1 + v2) / 2
2.05 m/s = (2.01 m/s + v2) / 2
v2 = 2.09 m/s