I am given the speed in km/h (s) and total stopping distance in meters (t)

Using the rule t = as^2 find values from 100 to 150.

I looked in my pre-calc book and there is an equation for stopping distance which is d = v +(v^2/20) and this confused me. I did not get the same results, is it because it is in mpr and not kmr.

Thank You,

Keith