I tell a story to two of my friends. Some of them repeat the story to two others, and in turn some of these pass the story on. Each time the story is told, it is told to two new people, and no one hears the story twice. Sometime later, 335 people know the story. How many people have related the story to others?

Suggestion: Use the following formula.

Number of vertices = 2 × Number of parents + 1

671= 2 x 335+1 That's how I did it and I was wrong.

motorcycle2008
Feb 3, 2018

#1**+2 **

I think your logic is not correct, unfortuantely. If you have heard the story, you have not necessarily "related the story to others." Let's say, for example, that there were 20 storytellers. Since each storyteller tells 2 people, there are 40 people who have been told the story. Now, 60 know about the story, only 20 of which are now storytellers, or "parents."

When you solved and you got 671, you found the number of people who know the story to be 671, but the prompt explains that only 335 people know the story. If I am understanding the problem correctly, 335 should go in for the number of people who know the story, or the "Number of vertices"

\(335=2x+1\\ 334=2x\\ 167=x\)

167 equals the number of parents, or the number of storytellers.

TheXSquaredFactor
Feb 3, 2018

#1**+2 **

Best Answer

I think your logic is not correct, unfortuantely. If you have heard the story, you have not necessarily "related the story to others." Let's say, for example, that there were 20 storytellers. Since each storyteller tells 2 people, there are 40 people who have been told the story. Now, 60 know about the story, only 20 of which are now storytellers, or "parents."

When you solved and you got 671, you found the number of people who know the story to be 671, but the prompt explains that only 335 people know the story. If I am understanding the problem correctly, 335 should go in for the number of people who know the story, or the "Number of vertices"

\(335=2x+1\\ 334=2x\\ 167=x\)

167 equals the number of parents, or the number of storytellers.

TheXSquaredFactor
Feb 3, 2018