If the communication lifetime of civilizations in our galaxy is 100 million years and our galaxy is 13 billion years old, what is the chance of us detecting another intelligent civilization now?
A) 1 in 1,300,000
B) 1 in 13
C) 1 in 1300
D) 1 in 130

Question

Quizplus · Accepted Answer

The chance of detecting another civilization is the ratio of the communication lifetime to the age of the galaxy, which is 100 million years divided by 13 billion years, simplifying to 1 in 130.

If the Communication Lifetime of Civilizations in Our Galaxy Is