A person borrows some money for 4 years at the rate of simple interest. If the ratio of principal and total interest is 5 : 1, then what is the rate ( in percentage) of interest?
A shopkeeper, sold cocoa seeds at the rate Rs 1,230 a kg and bears a loss of 5%. Now if he decides to sell it at Rs 1,353 per kg, what will be the result?
The ten's digit of a 2-digit number is greater than the units digit by 7. If we subtract 63 from the number, the new number obtained is a number formed by interchange of the digits. Find the number.