What is the present age of Subir? I. Subir's present age is half of his father's present age. II. After 5 years, the ratio of Subir's age to his father's age will be 6 : 11. III. Subir is 5 years younger than his brother.

Introduction / Context:
The task is to determine Subir’s current age from relationships involving his father (and optionally his brother). We will check which statements together give a solvable system.

Given Data / Assumptions:

• Let S = Subir's present age; F = father's present age.
• I: S = F / 2.
• II: (S + 5) : (F + 5) = 6 : 11.
• III: Subir is 5 years younger than his brother (irrelevant to S–F relationship unless the brother’s age connects to S or F numerically, which it does not here).

Concept / Approach:
Use I to express F in terms of S; plug into II to solve S uniquely. Evaluate other combinations for sufficiency.

Step-by-Step Solution:
From I: F = 2S.From II: (S + 5) / (F + 5) = 6 / 11 ⇒ 11(S + 5) = 6(F + 5).Substitute F = 2S: 11S + 55 = 6(2S + 5) = 12S + 30 ⇒ 55 − 30 = 12S − 11S ⇒ S = 25.Therefore, I + II together determine Subir’s present age uniquely: S = 25 years.I + III: Gives F in terms of S and a relation to the brother, but no numeric link to solve S ⇒ insufficient.II + III: The brother’s relation still does not connect to F in a way that fixes S ⇒ insufficient.

Why Other Options Are Wrong:
III is extraneous to solving S; using it with either I or II does not close the system. “All three” is overkill since I + II already suffice.

Common Pitfalls:
Trying to bring the brother into the age ratio unnecessarily; it does not add an equation linking S and F.

Final Answer:
Only Statements I and II are sufficient (Subir is 25 years old).