Line 15: Line 15:
 
 
 
The formula  $\forall x \exists y \exists (\neg F(x,y,t))$ says that for every person $x$, there exists a person $y$, and there
 
The formula  $\forall x \exists y \exists (\neg F(x,y,t))$ says that for every person $x$, there exists a person $y$, and there
exists a time $t$, such that $x$ cannot fool $y$ at time t i.e. No person can fool everyone all the time. So option <b>(B)</b> is correct.
+
exists a time $t$, such that $x$ cannot fool $y$ at time $t$ i.e., No person can fool everyone all the time. So option <b>(B)</b> is correct.
 
 
 
{{Template:FBD}}
 
{{Template:FBD}}
Line 21: Line 21:
 
[[Category: GATE2010]]
 
[[Category: GATE2010]]
 
[[Category: Logical Inference questions]]
 
[[Category: Logical Inference questions]]
 +
[[Category:Mathematics Questions from GATE]]

Revision as of 12:22, 29 June 2014

Suppose the predicate $F(x, y, t)$ is used to represent the statement that person $x$ can fool person $y$ at time $t$. which one of the statements below expresses best the meaning of the formula $\forall x \exists y \exists(\neg F(x,y,t))$?


(A) Everyone can fool some person at some time

(B) No one can fool everyone all the time

(C) Everyone cannot fool some person all the time

(D) No one can fool some person at some time

Solution by Happy Mittal

The formula $\forall x \exists y \exists (\neg F(x,y,t))$ says that for every person $x$, there exists a person $y$, and there exists a time $t$, such that $x$ cannot fool $y$ at time $t$ i.e., No person can fool everyone all the time. So option (B) is correct.




blog comments powered by Disqus

Suppose the predicate $F(x, y, t)$ is used to represent the statement that person $x$ can fool person $y$ at time $t$. which one of the statements below expresses best the meaning of the formula $\forall x \exists y \exists(\neg F(x,y,t))$?


(A) Everyone can fool some person at some time

(B) No one can fool everyone all the time

(C) Everyone cannot fool some person all the time

(D) No one can fool some person at some time

Solution by Happy Mittal[edit]

The formula $\forall x \exists y \exists (\neg F(x,y,t))$ says that for every person $x$, there exists a person $y$, and there exists a time $t$, such that $x$ cannot fool $y$ at time t i.e. No person can fool everyone all the time. So option (B) is correct.




blog comments powered by Disqus