Direction of the motion is same as the sign of the velocity.
i.e. positive velocity gives forward motion, negative velocity gives backward motion.
(1): When t=1s, velocity(v) is negative, no matter fefore or after 1s, so the direction of the motion is not changing, so (1) is false.
(2): Displacement is equal to the area under the v-t graph.
At t=2, area under v-t graph of particles P is = (2)(-2)/2 = -2m
Similarly, area under v-t graph of particles Q is 2m
Then, the different between P and Q is = 2-(-2) =4m
So (2) is true.
(3): Similar to (2), we can use the area to find the displacement of two particles.
displacement of P = 2m
displacement of Q = 8m
By comparison, P and Q is not in the same position
So (3) is false.