A and B launched a business with initial investments of Rs. 2000 and Rs. 3600, respectively. Three months into the venture, C came on board with an investment that was 25% higher than A's initial investment. Six months after the start, both A and B increased their stakes by injecting extra funds of Rs. 500 and Rs. 400, respectively. If the total profit at the end of the year amounted to Rs. 15850, calculate B's share of the profit.