Daisy's parents became concerned about the amount of time she was spending talking to her friends on the phone on school nights. They had decided to limit her phone usage to the hours 7:30pm to 8:30pm. Daisy's friends' parents thought this was a good idea and adopted the same policy.
Daisy and her group of friends decided they needed a way to connect with each other when there is an important message to spread. They knew long phone conversations would get them in trouble. After much discussion, the group decided that they can allow three minutes per phone call, thinking this would give enough time to get the
correct person on the phone and tell them the essential information.
This is their plan:

The next time Daisy learns something that she thinks is important for her group to know, she will call Jim at exactly 7:30. This call would take three minutes. At 7:33, Daisy will call Jarrod and Jim will call Alexis, relaying the same information, ending the calls at 7:36. At this time, these four will call four more people and so on.
How many of Daisy's friends could hear the news by 8:30?
You should be making certain assumptions during this task:
•It always takes three minutes to connect and complete a call
•Nobody calls someone that has already been called
•There is never a busy signal