A) You have the initial velocity (240 km/h, or 66.67 m/sec), the final velocity (zero), and the distance (95m), and you want to get the acceleration
Vfinal^2 = Vinitial^2 + 2ad
You know Vfinal, Vinitial, d, and you're trying to get a. A little rearranging, and the realization that Vfinal = 0 should get you to
a = -Vinitial / 2d
Note, a will be negative, since it's in the direction opposite the initial motion.
b) Once you finish part a, you now know the acceleration, and the final and initial velocities, and you have:
Vfinal = Vinitial + a*t
and since Vfinal is again zero, you end up with
Vinitial = -a*t t = -Vinitial / a
remember, a is negative, so even though there are negatives in this equation, it will all make sense.
Now, a little calculation, and you should get the answers