Mechanics help

Hi,

Could someone please help me with Q6b on the image attached. I understand where the 53 comes from but why do I need to add 11 and 4?

Thank you

The 53 (-53) is displacement from the origin after 10 seconds.
The particle starts at +7 m from the origin.

The particle then moves +4 m to the maximum point on the graph (at t = 2 s), -4 m down (at t = 4 s, where displacement from its starting position = 0), then a further -7 m (during the next 1.3 or so seconds) until its displacement from the origin = 0.

The 11 and 4 values come from 7 + 4 + 4

Does that make any sense? I always find it helps to draw/annotate a diagram