What strength of 20 ml acid should be added to 10 ml of 50% acid to get an average strength of 20% acid?

 Find the selling price of an article if a shopkeeper allows two successive discounts of 5% each on the marked price of Rs. 80.

If the price of petrol increases by 25% and Raj intends to spend only an additional 15% on petrol, by how much % will he reduce the quantity of petrol purchased?

A towel, when bleached, was found to have lost 20% of its length and 10% of its breadth. The percentage of decrease in area is

Anuradha purchased 30 kg of rice at the rate of Rs 11.50 per kg and 20 kg of rice at the rate of Rs 14.25 per kg. She mixed the two and sold the mixture. Approximately at what price per kg should she sell the mixture to make 30 per cent profit

The price of a VCR is marked at Rs. 12,000. If successive discounts of 15%, 10% and 5% be allowed, then at what price does a customer buy it?

What annual payment will discharge a debt of Rs. 1025 due in 2 years at the rate of 5% compound interest?

A trader gives 12% additional discount on the discounted price, after giving an initial discount of 20% on the labeled price of an item. The final sale price of the item is Rs.704. Find out the labeled price?

The difference between compound interest and simple interest on a sum for 2 years at 10% per annum, when the interest is compounded annually is Rs. 16. If the interest were compounded half-yearly, the difference in two interests would be:

The population of city is 80,000. If it increases 11% in the first year and decreases by 9% in the second year, what will be the population of the city after two years?