Shawna like to jog in the evening. One night, she noticed an unusual phenomenon. Aa she jogged, dogs would hear her and bark. After the first dog had barked for 15 seconds, two other dogs would join in and bark. In another another 15 seconds it seemed that each dog barking would inspire two more dogs to start barking. of course, long after Shawna passed the first dog, it continued to bark, as dogs are inclined to do. After 3minutes how many dogs were baking