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?
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