If a freely falling body in the last second travels a distance equal to the distance travelled in the first three seconds, the time of its travel is
 

A car accelerates from rest at a constant rate $\left(\alpha \right)$ for some time after which it decelerates at a constant rate $\left(\beta \right)$ and comes to rest. If the time elapsed is $t$, maximum velocity acquired by the car is

For the velocity-time graph shown in Fig. The distance covered by the body in the last two seconds of its motion is what fraction of the total distance covered in all the seven seconds?