Well, you need to find the distance traveled during the first second. So we need an equation that has the variables position acceleration and time which would be this...
X = Xo + Vot + 1/2 at^2
X=final position=what we want to find
Xo = initial position = 0
So if we plug in everything we get x=6.25
Now we need to find the distance traveled in the 12th second. We can easily find that by subtracting how far the vehicle travels in 11s from how far it travels in 12s. Use the eq above.