Aliens
Logic puzzles require you to think. You will have to be logical in your reasoning.
100 aliens attended an intergalactic meeting on earth.
73 had two heads,
28 had three eyes,
21 had four arms,
12 had two heads and three eyes,
9 had three eyes and four arms,
8 had two heads and four arms,
3 had all three unusual features.
How many aliens had none of these unusual features?
Answer
4 aliens.
Draw a venn diagram.
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Comments
zonarita
Apr 15, 2006
 I got 27. How did you get the answer 4? 
npf2005
Apr 16, 2006
 its pretty complicated 
(user deleted)
Apr 16, 2006
 I got 7 the first time but after seeing the answer I figured out where I went wrong 
roscoep
Apr 17, 2006
 Nice set and suset puzzle. 
roscoep
Apr 17, 2006
 Nice set and SUBset puzzle. 
brainster
Apr 17, 2006
 It was interesting to read, but I have to admit I did not reach the desired answer. Would love to see an explanation added to that for more information and clarity if you could! 
awishfulthinker
Apr 23, 2006
 You guys know how to draw venn diagrams??(you know the interconnecting circles) because thats how you solve this... I got 4 on my first try.
56 had only two heads
10 had only three eyes
7 had only 4 arms
9 had only two heads and three eyes
5 had only two heads and four arms
6 had only three eyes and four arms
3 had three eyes, four arms, and two heads.
if you draw the venn diagram its very easy 
NomadShadow
Apr 23, 2006
 Quite fun, but I didn't need to draw ven diagrams to solve this, it's just like the total area of three intersecting circles (C1 , C2 , C3). It's the sum of all areas minus the sum of all binary intersections plus the little area where all circles intersect.
In this case it was 73 + 28 + 21  12  9 8 + 3 = 96 alien with unusual features, leaving only 4 aliens without any of these features. lol 
tonjawithaj
Apr 28, 2006
 AWESOME!!! Woot! 
komoncents
May 05, 2006
 did you doublecount something? better sub it out. 
jeffmartin134
May 08, 2006
 i liked it 
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