In a certain time, the ratio of a certain principle and interest obtained from it are in the ratio 10 : 3 at 10 % interest per annum. The number of years for which the money was invested is? 

The difference between the simple interest and the compound interest on a certain amount at 5% for two years is 25, what is the amount?

The simple interest on a sum for 5 years is one fourth of the sum. The rate of interest per annum is

A sum triple itself in 9 years at simple interest. Find the rate of interest per annum is.

What sum will amount to ₹ 7000 in 5 years at $$3{1\over3}\%$$ simple interest ? 

Answer the following questions

Anshul borrowed Rs.24800 from Deepak at 8% p.a. simple interest for 4 years. He then added some more money to the borrowed sum and lent it to Rajeev for the same period at 10% p.a. If Anshul gains Rs. 5184 in the whole transaction, how much money did he add from his side?

In how much time will a sum of Rs. 12500 amounts to Rs. 20000 at the rate of 8 percent per annum at simple interest?

In what time will ₹ 72 become ₹ 81 at $$6{1\over4}$$ % per annum simple interest?