There are 7 streets to be named after 7 tree types. Ash, Birch, Elm, Maple, Oak, Pine, and Spruce. A city planner randomly selects the street names from the list of 7 tree types. Compute the probability of each of the following events. Event A: The first three streets are Birch, Spruce, and Ash, without regard to order. Event B: The first street is Pine, followed by Oak and then Birch. Write your answers as fractions in simplest form. P(A) = | P (B) = 0