Prabhat, Amit and Ankit enter into partnership business. Prabhat invested Rs. P, Amit invested Rs. 1200 more than Prabhat and Ankit invested Rs. 2400 more than Prabhat for 8 months, 10 months and 6 months respectively. If Prabhat got Rs. 27000 as profit share and Amit got Rs. 36000 as profit share, find amount invested by Ankit?