I got 5.68 m and I don't know whether it is correct or not
I did like this..
first I use this equation to get the acceleration:
v=v0+at
since we have v=-2.4 , t=10 and v0=0
then we got a=-0.24
then I used this formula (x2-x1)= v0(t2-t1) + 0.5a(t2-t1)^2
we have x2= -2 , v0=0 ...