Anil and Ruhi started a business with an initial investment of 5 : 8. After four months Anil doubled his investment and Ruhi reduced to 60% of initial investment and Sujeet joined them with the investment of the sum of Ruhi’s initial and Anil’s current investment. After 8 more months they distributed the profit in which Sujeet receives 18,000 then find the initial investment of Ruhi?