For the velocity time graph shown in figure, the total distance covered by the particle in the last two seconds of it motion is what fraction ‘f’ the total distance covered by it in all the seven seconds?

Distance covered in last two sec $=20\times 1+\frac{1}{2}\times 1\times 20$

$=20+10$

$=30m$

Total distance covered in all 7 seconds

$=\frac{1}{2}\times 2\times 20+4\times 20+\frac{1}{2}\times 1\times 20$

$=20+80+10$

$=110$

Fraction of distance covered in last two seconds at total distance

$=\frac{30}{110}=\frac{3}{11}$