Problem:
Naman and Aman can do some work together in 15 days. Naman and Baman can do the same work in 12 days. If all of them together are paid Rs. 375 to complete the work and Naman received Rs. 75 out of it, then find the time taken by Aman to finish the same work alone.

Given information:
- Naman and Aman can complete the work together in 15 days.
- Naman and Baman can complete the work together in 12 days.
- Naman received Rs. 75 out of the total payment of Rs. 375 to complete the work.

Assumptions:
- The work is considered as a unit of work.
- The efficiency of each person remains constant throughout the work.

Solution:
Let's assume that the efficiency of Naman is N, the efficiency of Aman is A, and the efficiency of Baman is B.

1. Calculation of the efficiency of Naman and Aman:
Since Naman and Aman can complete the work together in 15 days, their combined efficiency can be calculated as follows:
Efficiency of Naman and Aman = 1/15

2. Calculation of the efficiency of Naman and Baman:
Similarly, since Naman and Baman can complete the work together in 12 days, their combined efficiency can be calculated as follows:
Efficiency of Naman and Baman = 1/12

3. Calculation of Naman's efficiency:
Since Naman received Rs. 75 out of the total payment of Rs. 375, his share of the total efficiency can be calculated as follows:
Efficiency of Naman = 75/375 = 1/5

4. Calculation of Aman's efficiency:
Now, we can calculate Aman's efficiency by subtracting Naman's efficiency from the combined efficiency of Naman and Aman:
Aman's efficiency = Efficiency of Naman and Aman - Efficiency of Naman
Aman's efficiency = 1/15 - 1/5 = 1/15 - 3/15 = -2/15

5. Calculation of Baman's efficiency:
Since the combined efficiency of Naman and Baman is known, we can calculate Baman's efficiency by subtracting Naman's efficiency from it:
Baman's efficiency = Efficiency of Naman and Baman - Efficiency of Naman
Baman's efficiency = 1/12 - 1/5 = 1/12 - 12/60 = -7/60

6. Calculation of Aman's time:
To find Aman's time taken to complete the work alone, we can use the formula:
Efficiency = 1/Time
Aman's efficiency = -2/15
Therefore, -2/15 = 1/Time
Time = -15/2

7. Final Answer:
As time cannot be negative, we can conclude that Aman cannot complete the work alone. Hence, it is not possible to determine the time taken by Aman to finish the same work alone.

Conclusion:
Based on the given information and calculations, it is not possible to determine the time taken