how to solve this mechanics question

2. A car moves along a straight horizontal road with constant acceleration a m s –2 where a > 0
The car is modelled as a particle.
At time t = 0, the car passes point A and is moving with speed ums–1 In the first three seconds after passing A the car travels 20 m.
In the fourth second after passing A the car travels 10 m.
The speed of the car as it passes point B is 20ms–1
Find the time taken for the car to travel from A to B.

Reply 1

averageviolinist

did this in a hurry so not very sure. I got 9.5 seconds. Pretty sure theres a shorter method than what I did. (would be great if someone else also attempted so I can see if mine was correct 😁)