An office has 60 employees with an overall average salary of Rs. 12,000 per month. If the number of executives is twice the number of non-executives, what is the average salary of the non-executive employees?

Introduction / Context:
Weighted-average questions require either the subgroup averages or enough relations between them to solve for unknowns. Knowing only the overall mean and headcount ratio often isn’t sufficient.

Given Data / Assumptions:

• Total employees = 60
• Executives : Non-executives = 2 : 1 ⇒ Executives = 40, Non-executives = 20
• Overall average salary = Rs. 12,000
• No subgroup averages provided.

Concept / Approach:
Let average salaries be E for executives and N for non-executives. Then overall average gives a single equation: (40*E + 20*N) / 60 = 12000. With two unknowns (E and N) and only one equation, infinitely many solutions exist unless another constraint is given.

Step-by-Step Solution:

Verification / Alternative check:
Pick E = 13000 ⇒ 40*13000 = 520000, then 20*N = 200000 ⇒ N = 10000. Pick E = 11000 ⇒ 40*11000 = 440000, then 20*N = 280000 ⇒ N = 14000. Multiple feasible values show non-uniqueness.

Why Other Options Are Wrong:

• Rs. 9000, Rs. 8000, Rs. 6000: Each is a specific value without justification; many values are possible.
• None of these: Insufficient data is properly captured by “can't be determined.”

Common Pitfalls:
Assuming executives are always paid more and plugging a guess; the problem does not state subgroup averages or ordering constraints.

Final Answer:
can't be determined