Une urne contient 12 boules indiscernables au toucher. 5 noires, 6 rouges et une bleue. On tire successivement et sans remise deux boules de l'urne. Calculer la probabilité des événements suivants: ∶ " 2 " ∶ " 2 " ∶ " 1 1 " ∶ " 2 " ∶ " 1 "

An observer(o) spots a plane(p) taking off from a local airport and flying at a 29 degree angle horizontal to her line of sight and located directly above a tower(t). the observer also notices a bird circling directly above her. if the distance from the plane(p) to the tower(t) is 6,000ft., how far is the bird(b) from the plane(p).