Question

Four people P, Q, R, and S, of different ages, make the following observations.
P - I am younger than S.
Q - I am neither the youngest nor the oldest.
R - P is older than me.
Based on these observations, the youngest person is ______.

• A. P
• B. Q
• C. R
• D. S

Hint:

Turn each statement into a "younger than" relation first, then check which single person is younger than all three of the others without breaking any statement.

Answer 1

The Correct Option is C

Instead of chaining the comparisons, let's test each option directly against the three statements and see which one survives.

1. Testing P as youngest: R says "P is older than me", which directly means P is older than R. If P were the youngest of all four, P would have to be younger than R too, but that contradicts R's own statement. So P cannot be the youngest.
2. Testing Q as youngest: Q says "I am neither the youngest nor the oldest". If Q were the youngest, Q's own statement would be false. So Q cannot be the youngest.
3. Testing S as youngest: P says "I am younger than S", which means P is younger than S. If S were the youngest of all four, S would have to be younger than P too, but that contradicts P's own statement. So S cannot be the youngest.
4. Testing R as youngest: We need R younger than P, younger than Q, and younger than S. R younger than P is given directly by R's own statement. R younger than S follows since R is younger than P and P is younger than S. R younger than Q holds too, because if R were older than Q, Q would become the overall youngest, which breaks Q's statement, so Q must be older than R.

Only the fourth case, R as the youngest, avoids every contradiction, so R must be the youngest person.

Let's summarize:

• R's own statement rules out P as the youngest.
• Q's own statement rules out Q as the youngest.
• P's statement rules out S as the youngest.
• Only R is left once the other three are ruled out, and checking R directly confirms it works.

So the youngest person is R.