‘A’ and ‘B’ started a business by investing Rs. 7,000 and Rs. 8,000, respectively. 6 months later, ‘C’ joined them with an investment equal to average of initial investment made by ‘A’ and ‘B’ together. If at the end of the year, B’s profit share out of the total profit was Rs. 40,000, then find the profit share of ‘C’.