Ratio Today — “At present Arun : Deepak = 4 : 3. After 6 years, Arun will be 26. What is Deepak’s present age?”

Introduction / Context:
We first recover Arun’s present age from the future statement, then use the 4:3 ratio to scale down to Deepak’s present age proportionally.

Given Data / Assumptions:

• Arun in 6 years = 26 ⇒ Arun now = 20.
• Present ratio A:D = 4:3.

Concept / Approach:
If 4 parts correspond to 20 (Arun), then 1 part is 20/4 = 5; Deepak has 3 parts, so 3 * 5.

Step-by-Step Solution:

Verification / Alternative check:
In 6 years: Deepak 21; ratio becomes 26:21 which simplifies close to 4:3 given the fixed initial ratio used for present ages. The present ages are consistent with the given data.

Why Other Options Are Wrong:
12/19/25/13 do not equal (3/4) of 20.

Common Pitfalls:
Applying the 4:3 ratio to the future ages instead of to the present ages; or forgetting to first compute Arun’s present age.

Final Answer:
15