Here average speed for given motion is defined as ratio of total distance covered by total time
so here we can say
[tex]v = \frac{d}{t}[/tex]
here total distance can be calculated by formula
distance = speed * time
[tex]v = \frac{v_1*t_1 + v_2*t_2}{t_1 + t_2}[/tex]
here given that its average speed is v = 2.05 m/s
for first half let the time is "t " seconds and the speed for that is 2.01 m/s
and for next half time will be same and it is "t " seconds again
so by plug in all data in above equation we have
[tex]2.05 = \frac{2.01* t + v* t}{t + t}[/tex]
[tex]2.05 * 2 = 2.01 + v[/tex]
[tex]v = 2.09 m/s[/tex]
so its speed for next half must be 2.09 m/s