Question

Consider the following statements and answer the question.

M, N, O and P are all different individuals.
M is the daughter of N.
N is the son of O.
O is the father of P.

Which among the following statements is contradictory to the above premises?

• A. P is the father of M.
• B. O has three children.
• C. M has one brother.
• D. M is the granddaughter of O.

Hint:

Work out who M's father already is from the given facts, then see which option secretly repeats that role under a different name.

Answer 1

The Correct Option is A

Step 1: Understanding the Question:
We are given four family facts about M, N, O and P, who are stated to be four different individuals. We need to find which one of the four given statements cannot possibly be true if we accept those four facts.

Step 2: Key Formula or Approach:
The cleanest way to solve this is to first draw out the family tree from the given facts, work out each person's generation and gender where possible, and then test each option against that tree.

Step 3: Detailed Explanation:
"N is the son of O" tells us N is male and O is one generation above N.
"O is the father of P" tells us O is male and P is a child of O, so P and N are both children of O, making N and P siblings.
"M is the daughter of N" tells us M is female and M is a child of N, one generation below N, which makes M the grandchild of O.
Check option (4) first: "M is the granddaughter of O" is exactly what we just worked out, so this statement agrees with the premises, it is not contradictory.
Now check option (1): "P is the father of M." We already showed M's father is N. Since M, N, O and P are all different individuals, P cannot also be N. If P were the father of M, P would have to be the same person as N, which directly breaks the "all different individuals" condition. So this statement cannot be true alongside the given premises, it is contradictory.
Now check option (2): "O has three children." We only know for certain that O has two children, N and P. Nothing in the premises says O cannot have a third child, so this is simply extra information that is not ruled out.
Now check option (3): "M has one brother." We are not told whether N has any other children besides M, so M having one brother is a possibility left open by the premises.

Step 4: Final Answer:
Only option (1) directly clashes with the given facts, because it would force P and N to be the same person, which the question already forbids.