Numerical because its the number of assistants.
Um.... I am confused I do not know what u are asking me.
I am so sorry that I can not help , but isf I knew it I would help.
When graphs are plotted, graphs as in the .jpeg image in attachment are obtained.
First graph is line going through ordered pair (point) (0,6) and pair (6,8).
The second graph is line going through ordered pair (6,8) and pair (8,0).
Intercept of these graphs is point (ordered pair) (6,8).
You see from the .jpeg image that the following is true:
Initial velocity of the runner is 6 meters per second (runner starts with this velocity), for a while he runs, velocity grows, then in the 6th second (time=6), runner starts to slow down and velocity starts to decrease, and runner stops totally at time = 8.
So runner stops after 8 seconds.
The 4th claim (sentence) is correct.