A body initially at rest is moving with uniform acceleration a. Its velocity after n seconds is v. The displacement of the body in last 2 s is

u = 0, after n seconds

V= an ⇒ a = V/n

Velocity after (n – 2)sec

v = u + at ⇒v = 0 + a(n–2)

v = a(n – 2)

Displacement in last 2 sec

$\begin{array}{l}\mathrm{s}=\mathrm{vt}+\frac{1}{2}{\mathrm{at}}^2\\ \mathrm{s}=\mathrm{a}(\mathrm{n}-2)2+\frac{1}{2}\mathrm{a}\left(2^2\right);\left[\mathrm{a}=\frac{\mathrm{v}}{\mathrm{n}}\right]\\ \mathrm{s}=2(\mathrm{n}-2)\frac{\mathrm{v}}{\mathrm{n}}+\frac{1}{2}\frac{\mathrm{v}}{\mathrm{n}}\cdot 4=\frac{2\mathrm{v}}{\mathrm{n}}(\mathrm{n}-1)\end{array}$