Correct Answer - 2

`s = (t^(3))/(3) - (3t^(2))/(2) + 2t`

`:. V = (ds)/(dt) = t^(2) - 3 t + 2`

Since the particle comes to rest, therefore,

`t^(2) - 3 t + 2 = 0`

`(t - 1) (t - 2) = 0`

` t = 1 s " and " 2s`

Hence, the particle comes to rest twice.

`:. n = 2`