If average and instantaneous velocities are same,then what is the type of motion?

If a body starts from rest and travels $120 \, cm$ in the $6^{th}$ second,then the acceleration of the body is:

The maximum possible acceleration of a train moving on a straight track is $10 \ m/s^2$ and maximum possible retardation is $5 \ m/s^2$. If the maximum achievable speed of the train is $10 \ m/s$,then the minimum time in which the train can complete a journey of $135 \ m$ starting from rest and ending at rest is ......... $s$.

$A$ particle moves along the $x$-axis as $x = 4(t-2) + a(t-2)^2$. Which of the following statements is true?

An object moving along the $x$-axis with a uniform acceleration has a velocity $\vec{v} = (12 \ cm \ s^{-1}) \hat{i}$ at $x = 3 \ cm$. After $2 \ s$,if it is at $x = -5 \ cm$,then its acceleration is:

$A$ body starts from rest with uniform acceleration. If its velocity after $n$ seconds is $\upsilon$,then its displacement in the last two seconds is