A sum of money becomes 3 times in 12 years. In how many years it will become 5 times at the same rate of simple interest?

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

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? 

The difference of simple interest from two banks on ₹8,000 in 3 years is ₹800. If the rate of interest per annum in two banks are R1 and R2, then what is the value of R1 - R2? (Where R1 > R2)

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

Any money at the rate of simple interest becomes Rs 1143 in 3 years and Rs 1305 in 5 years Find the rate of principal and 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. 

The difference between simple interest and compound on Rs. 1200 for one year at 10% per annum reckoned half-yearly is: