Your challenge is too find out where the truck is after 15 seconds.
The picture cannot tell us - the truck is out of sight at t = 15! But we can deduce a mathematical model of the motion and then use the model to predict where the truck will be!
You can of course find (t, x) pairs by pausing the movement and clicking in the graph.
But rather click on "show data in table" and then click (re)start. Now it is easy? Explain your method!