Aman, Preeti, and Shristi started a partnership with an investment of Rs. X - 1200, Rs. X and Rs. X + 1800 respectively. If the profit of Preeti is invested in a scheme at the rate of 18% p.a simple interest for 5 years, then the interest received is Rs. 3600. If the total profit of the business is Rs. 4800 more than twice the profit of Preeti, then which of the following statement(s) is/are true?

I. Sum of the Investment of Aman and Preeti is equal to the investment of Shristi 

II. Value of X is a multiple of 18

III. Aman gets 18.75% of the total profit