An article is listed at Rs. 5,000 and two successive discounts of 12% and 12% are given on it. How much will the seller gain or lose if he gives a single discount of 24%?

The marked price of an article is 50% above cost price. When marked price is increased by 20% and the selling price is increased by 20%, the profit doubles. If original marked price is Rs 300, then the original selling price is:

A boat covers 12 km upstream & 18 km downstream in 3 hrs, while it covers 36 km upstream & 24 km downstream in 6.5 hrs. What is the speed of the current?

25 persons can complete a work in 60 days. They started the work. 10 persons left the work after x days. If the whole work was completed in 80 days, then what is the value of x ?