Tonu started a business investing Rs. 90,000. After 3 months, reetu joined him with a capital of Rs. 1,20,000. After 6 months, shalu joined them with a capital of Rs.1,80,000. At the end of the year, they made a profit of Rs.33000. find the share of shalu. A) 13200 B) 6600 C) 7500 D) 12000