C brings Rs 60,000 for 1/3 share in the firm.
Using C's contribution to find the capitalised value of the entire firm:
If 1/3 share = Rs 60,000
Then, Total capitalised value of firm = Rs 60,000 × 3 = Rs 1,80,000
Calculating the actual combined capital of all partners:
A's capital = Rs 45,000
B's capital = Rs 45,000
C's capital = Rs 60,000
Total combined capital = Rs 45,000 + Rs 45,000 + Rs 60,000 = Rs 1,50,000
Goodwill = Capitalised value - Combined capital
Goodwill = Rs 1,80,000 - Rs 1,50,000 = Rs 30,000
The logic here is that C values the entire firm at Rs 1,80,000 (since he pays Rs 60,000 for one-third share). However, the actual capital available is only Rs 1,50,000. This difference of Rs 30,000 represents the firm's goodwill - the premium value of the existing business beyond its capital.
Answer: Option 4 - Rs 30,000