A can do as much work in 4 days as B can do in 5, and B can do as much work in 6 days as C in 7. In what time will C do a piece of work which A can do in a week ?
The list price (marked price ) of an article is Rs. 900 and is available at two successive discounts of 20% and 10% ; the selling price of the article,in rupees, is