A man purchased 120 reams of paper at INR 80 per ream. He spent INR 280 on transportation, paid octroi at the rate of 40 paise per ream and paid INR 72 to a porter. In order to gain 8%, he must sell each ream of paper for :

A man retired from his service at the age of 60. He served for 3/5th years of his retirement age. He joined his job at the age of :

The ratio of the areas of two squares one having double its diagonal than the other is

The radius of a sphere is doubled. The percentage of increase in its surface area is

A dealer marks his goods 20% above cost price. He then allows some discount on it and makes a profit of 8%. The rate of discount is :

The price of electricity has been increased by 25%. If a person wants to keep the expenditure same, then the percentage reduction in use of electricity should be :