X, Y and Z entered into a partnership with some investment for one year. After one-year X got 2/5 profit and Y and Z got equal part of remaining profit. If total profit after one year is 15% instead of 10% then X got 900 Rs. more. Find the investment of Y.

X gets 2/5 of profit at 10% total profit. When profit increases to 15%, X gets Rs. 900 more. The additional 5% profit on total investment gives X an extra 2/5 of that increment. Let total investment = I. 0.05 × I × (2/5) = 900, so I = 45000. X's investment = (2/5) × 45000 = 18000. Y and Z share remaining 3/5 equally, so Y gets (3/10) × 45000 = 13500. Answer D is correct.