Chandan is 2 years older than Ankit but 1 year younger than Sumit. Ankit is twice as old as Khushboo. If Khushboo's present age is 25 years, what is the present age (in years) of Sumit?

Introduction / Context:
This question connects the ages of four people: Chandan, Ankit, Sumit and Khushboo. We are given age differences and a multiple relationship, along with Khushboo's present age. Our goal is to determine Sumit's present age. This problem exercises your ability to chain age relationships step by step.

Given Data / Assumptions:

- Chandan is 2 years older than Ankit.
- Chandan is 1 year younger than Sumit.
- Ankit is twice as old as Khushboo.
- Khushboo's present age is 25 years.
- All ages are in years and positive.

Concept / Approach:
We start by using Khushboo's known age to determine Ankit's age through the "twice as old" relationship. Then we use the differences to find Chandan's age and finally Sumit's age. The key is to move along the chain of relationships carefully, one step at a time, always substituting known values into the next relation.

Step-by-Step Solution:
Step 1: Khushboo's present age is given as 25 years. Step 2: Ankit is twice as old as Khushboo. Therefore, Ankit's present age = 2 × 25 = 50 years. Step 3: Chandan is 2 years older than Ankit. So Chandan's present age = 50 + 2 = 52 years. Step 4: Chandan is 1 year younger than Sumit, meaning Sumit is 1 year older than Chandan. Step 5: Sumit's present age = 52 + 1 = 53 years.

Verification / Alternative check:
We can verify by checking all relations. If Khushboo is 25 years old, Ankit is 50 years old, which is indeed twice 25. Chandan is 52, which is 2 years older than Ankit (50 + 2), and Sumit is 53, which is 1 year older than Chandan (52 + 1). Every relationship exactly matches the statements in the question, confirming that Sumit's present age is 53 years.

Why Other Options Are Wrong:
Ages such as 50, 51, 52 or 55 years for Sumit contradict at least one of the given relationships. For example, if Sumit were 52, Chandan could not be both 1 year younger than Sumit and 2 years older than Ankit when Ankit is 50. Only 53 years keeps all differences and multiples consistent.

Common Pitfalls:
Students sometimes mix up "older" and "younger" relationships or forget which person is being compared to which. Another frequent mistake is to apply the "twice as old" relationship to the wrong pair. A useful strategy is to start with the person whose age is known (Khushboo), calculate each subsequent age in sequence, and write a small diagram or list to track each step.

Final Answer:
Sumit's present age is 53 years.