RBI Assistant Prelims 2015 Sitting 2 Paper

A started a business with an investment of Rs. 16,000. After 6 months from the start of the busi- 89 ness, B and C joined with Rs. 12,000 and Rs. 18,000 respectively and A invested an additional amount of Rs 4000. If the difference between A's share and B's share is the annual profit is Rs. 6000, what was the annual profit received?