If A + B means that A is the father of B, A - B means that A is the mother of B, A  × B means that A is the brother of B then which of the following expression shows that Q is the son of P?

P − Q × R

Checking from the option, we get the answer from option (iv):

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Please note:

  l   ⇒ Vertical line shown "generation gap".

 =  ⇒ Double lines shown "relation of spouse" 

—  ⇒ Horizontal line shown "relation in same generation other than spouse".

     ⇒ Rectangular box shown " Male".

     ⇒ Circular box shown " Female".

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