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Solution for x implies y part II

2 5 F E.
The rule states that "an odd number card should have a vowel on the other side.". Question is how many minimum cards from above should be turned to make sure that this rule is followed, and what are they.

Answer: 2 cards. They are 5 and F.
E does not have to be turned because regardless of what is on the other side, the rule to the word would be still true.
F has to be turned over ot ensure that it does not have an odd number behind it.

Raghuram
Thursday, January 02, 2003

Part I

(you can't use paper, you have to figure it out in your head)

i have a black triangle, a white triangle, a black circle and a white circle.  if i gave you a shape (triangle or circle) and a color (black or white), the "frobby" items would be those that had either the shape or the color, but not both.  that is, in order to be frobby, the item must be of the specified color OR the specified shape, but not both the specified shape AND the specified color.  i'm thinking of a shape and a color in my head and i tell you that the white triangle is frobby.  can you tell me the "frobbiness" of the other items?

Solution to part 1.
The person was thinking either of a white circle or of a black triangle. Only these two would allow for the white triangle's frobbiness.
Say she was thinking of a white circle. The only other frobby item would have to be the black circle (the white triangle's taken by her already).
Say she was thinking of a black triangle. The only other frobby item would have to be the black circle (the white triangle ...).
So in short, in either case the only other frobby item would have to be the black circle.

Leora Wiseman
Sunday, January 26, 2003

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