Explanation:

Let’s break this down:

- Each friend gets 8% per annum on their own capital:

- Friend 1: Rs. 48000 × 8% = Rs. 3840

- Friend 2: Rs. 52000 × 8% = Rs. 4160

- Friend 3: Rs. 36000 × 8% = Rs. 2880

- Total fixed payouts = Rs. 3840 + Rs. 4160 + Rs. 2880 = Rs. 10880

- Subtract that fixed payout from the total profit:

- Rs. 32640 - Rs. 10880 = Rs. 21760 (this gets split in ratio of capitals)

- Their investment ratios:

- 48000 : 52000 : 36000

- Divide each by 4000 for easy numbers: 12 : 13 : 9

- Total parts: 12 + 13 + 9 = 34

- Share of the first friend (12 parts):

- (12/34) × Rs. 21760 = Rs. 7680

- Add his 8% interest:

- Rs. 3840 + Rs. 7680 = Rs. 11520

So, the correct answer is:

Option 4: Rs. 11520

Option analysis:

- Option 1 and 2 (Rs. 11340 and Rs. 11000) both are too low—those would underestimate both share and interest.

- Option 3 (Rs. 12500) overshoots.

- Option 4 gets it bang on: Rs. 11520.

That’s all there is to it.