'A' and 'B' start a business by investing Rs. 8,000 and Rs. 12,000, respectively. Five months later, they invite 'C' to join the business who invested Rs. 'R'. If at the end of the year, the profits were divided among 'A', 'B', and 'C' in a ratio of 2:3:5, respectively, then find the value of 'R' in terms of 'P' given that 'P' = 3,000.