Arowboat passenger uses an oar to push the boat off the dock by exerting a force of 60.0 n for 2.0 s. what impulse acts on the boat?

By definition, the impulse is given by the product of the average force multiplied by the time interval in which this force is applied.
 In other words, the impulse is:
 I = F * delta t
 Substituting the values:
 I = (60.0) * (2.0)
 I = 120.0 N * s
 
 impulse acts on the boat is I = 120.0 N * s