200 litres of mixture contains 15% water and the rest is milk. The  amount of milk that must be added so that the resulting mixture contains 87.5 % milk is:

The ratio between the ages of a father and his son four year ago was 19:6. If the difference between the ages of the father and son is 26 years, what will be the ratio of their present ages?

A motor car finishes a journey in 10 hours. The first half at 21 km/hr. and the rest at 24 km/hr. Find the distance?

Two pipe can fill a cistern in 3 hours and 4 hours respectively and a waste pipe can empty it in 2 hours. If all  the three pipes are kept open, then the cistern will be filled in

8 men working for 9 hours a day complete a piece of work in 20 days. In how many days can 7 men working for 10 hours a day complete the same piece of work?

A and  B can complete a work in 15 days and 10 days respectively. They started doing the work together but after 2 days B had to leave and A alone completed the remaining work. The whole work was completed in-

A shopkeeper sells a watch set on discount of 8% of printed price and gain 25 %. If marked price was Rs. 20,000 then, what was the cost price?

A sells a good to B at a profit of 20% and B sells it to C at a profit of 25%. If  C pays Rs. 225 for it, what was the cost price of A?