A person borrows 5,000 for 2 years at 4 % per annum simple interest. He immediately lends it to another person at $$6{1\over 4}\%  $$ per annum simple interest for 2 years. His gain in this transaction is 

In what time will the annual simple interest rate at $$ {6{1\over4}{\%}}$$ , 72 rupees becomes 81 rupees?

A sum of Rs.1600 gives a simple interest of Rs.252 in 2 years and 3 months. The rate of interest per annum is 

A person invested some amount at the rate of 12 % simple interest and a certain amount at the rate of 10 % simple interest for 1 year. He received yearly interest of Rs. ₹ 130, but if he had interchanged the amount invested, he would have received 4 more as interest. How much did he invest at 12 % simple interest? 

A sum of money lent out at simple interest amounts to ₹720 after 2 years and 1020 after a further period of 5 years. Find the principal. 

What equal installment of annual payment will discharge a debt which is due as ₹ 848 at the end of 4 years at 4 % per annum simple interest? 

Rs. 1,080 invested for 3 months gave an interest of Rs. 27. The simple rate of interest per annum was :

The principal which gives ₹ 1 interest per day at a rate of 5 % simple interest per annum is