Five years ago, the average age of Rashmi and Surbhi was 20 years. Now, the average age of Rashmi, Surbhi, and Meeta is 30 years. What will be Meeta’s age after 15 years?

Introduction:
Convert averages to totals at each time point and account for aging to isolate the newcomer’s present age. Once Meeta’s current age is known, projecting 15 years ahead is straightforward addition.

Given Data / Assumptions:

• 5 years ago: avg(Rashmi, Surbhi) = 20 → sum then = 40.
• Now: avg(Rashmi, Surbhi, Meeta) = 30 → current sum of three = 90.
• Rashmi and Surbhi each aged 5 years since the earlier snapshot.

Concept / Approach:
Current (R + S) = 40 + 5 + 5 = 50. Then Meeta now = 90 − 50. Add 15 to get Meeta’s age after 15 years.

Step-by-Step Solution:

Verification / Alternative check:
Totals align with given averages: (R + S + M) now = 90. Aging arithmetic is linear and consistent.

Why Other Options Are Wrong:
35 and 39 correspond to earlier time points; 67 overshoots by adding aging twice; 45 is Meeta’s age in 5 years, not 15 years.

Common Pitfalls:
Forgetting that both Rashmi and Surbhi aged 5 years each or mixing up projection intervals.

Final Answer:
55 yr