Suppose there are a million habitable planets in our galaxy, that ...

[P68T]

Suppose there are a million habitable planets in our galaxy, that one in ten are habitable, that one in a thousand planets with life had at some point had an intelligent civilization, and that one in a hundred civilizations that has ever existed is
 
  in existence now. Given this, how many civilizations are in existence now? A) 10
  B) 1
  C) 1000
  D) 100

Question 2

Gasoline yields 4.8  107 joules per kg when burned. The density of gasoline is approximately the same as that of water, and 1 gal = 3.8 L. How much energy does your car use on a trip of 100 mi if you get 25 mi per gallon?
 
  What will be an ideal response?

[Pamela.irrgang@yahoo.com]

Answer to Question 1

B

Answer to Question 2

7.3  108 J