Sets algebra

Question

 For any three sets $P$,$Q$ and $R$, $s$ is an element of $(P \bigtriangleup Q)\bigtriangleup R$  if $s$ is in

1. Exactly one of $P$,$Q$ and $R$
2. at least one of $P,Q,R$ but not in all three of them at the same time
3. exactly two of $P,Q$ and $R$  
4. exactly one of $P,Q$ and $R$ or in all the tree of them.

Comments

Oh yes i missed that option D will be the correct answer.

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Pls explain how?

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Let A = (PΔQ)ΔR

Check it when s belongs to exactly one of P,Q and R does s belongs to A

Then check when s belongs to exactly two of P,Q and R does s belongs to A.

Then checj when s belongs to all three of them does s belongs to A

You will get your answer

Answer 1

Is it correct?

Comments

Thanks. i understood the left part but what did you do in the right part taking three S as P,Q and S?

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In the right part,I took the element S in all three sets namely P,Q and R and then solved.You may solve like this too both are correct

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Thanks.