Question : Directions: If A + B means that A is the father of B, A × B means that A is the mother of B, and A – B means that A is the brother of B then which of the following expressions shows that P is the paternal grandmother of R?

Option 1: Q × P + R

Option 2: P × Q – R

Option 3: P + R × Q

Option 4: P × Q + R

Correct Answer: P × Q + R

Solution : Let's check the given options –
First option: Q × P + R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female in the figure. So, from the above family tree, it is evident that P is the father of R.
Second option: P × Q – R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female in the figure. So, from the above family tree, it is evident that P is the mother of R.
Third option: P + R × Q
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female in the figure. So, from the above family tree, it is evident that P is the father of R.
Fourth option: P × Q + R
According to the given expression, the family tree will be as follows –

Here, the quadrilateral represents the male, and the circular figure represents the female in the figure. So, from the above family tree, it is evident that P is the paternal grandmother of R.

Hence, the fourth option is correct.