test series

Question

please someone explain the approach?

Comments

Option C ???

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yes but can u please explain this?

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I give you simple example :

Premises => Conclusion

P  => (PVQ)

it means that assume that Premises are true and then check whether conclusion is true of not

i:e in that case we assume P is true

therefore P V Q  must be true (T V T = T or T V F = T)

whether Q is True of False we always get conclusion as true  

another example

P , Q ==> P ^ Q

premises are true means P and Q is true

therefor P ^ Q also true (T ^ T = T)

 

P --> Q , Q ==> P

we assume that premises are true

(~p V Q) ^  ~P {premises only True when ~P is True right}

but if ~P is true

then in conclusion P should be false  right

therefore it's invalid