Question

Lori is president of a book club. She has a message she wants to get out to her book club members. On

Monday, she called one member and asked that member to call two other members by noon the next day and
repeat the message. How many calls were made by Friday afternoon?

Answer 1

31 calls

Explanation:

This method of information dissemination forms a tree diagram with a common factor of 2 for each next day.

On Monday, Lori made a call.

By noon on Tuesday (the next day), two calls were made by the initial member.

By noon on Wednesday, four calls would be made by the two members.

By noon on Thursday, eight calls would be made.

By noon on Friday, sixteen calls would be made.

Therefore,

total calls made by Friday afternoon = 1 + 2 + 4 + 8 + 16

= 31