<PRE><B>Question 1081543</B>
Make a Venn diagram with 3 overlapping circles.
You should be able to count 7 distinct regions.
The region in the center is the generals who
served in G, R, and S. Call that region X.
G = 14
R = 12
S = 10
G AND R = 6
G AND S = 4
R AND S = 3
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The trick now is to identify each of the 7 distinct regions
so that you have eliminated all the overlaps.
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A little shortcut is to lump together the 4 regions that make
up G. That gives you 14.
Then I get 2 more regions from R minus overlap with G
Then I get 1 more which is S and ONLY S ( no overlaps )
4 + 2 + 1 = 7
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14 +
12 - 6 
10 - 4 - ( 3-x )
This should add up to 25
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14 + 12 - 6 + 10 - 4 - 3 + x = 25 
23 + x = 25 
x = 2 
That means there are 2 generals who seved in
Gulf War, Russia, and Syria.
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Hope this helps. The key is to add up the 7 regions
without overlaps to find x
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Now you can check by adding up each of the 7
(1) 14 - 4 - ( 6-2 )
(2) 12 - 6 - ( 3-2 )
(3) 10 - 4 - ( 3-2 )
(4) 4 - 2
(5) 6 - 2
(6) 3 - 2
(7) 2
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Add them up
(1) 6
(2) 5
(3) 5
(4) 2
(5) 4
(6) 1
(7) 2
---------
25 total

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