What is the simple interest when Rs. 13000 get the interest Rs. 6,370 in the $$ {3{1\over 2}}$$ year?

The simple interest on a sum of money is 4 / 9 of the principal and the number of years is equal to the rate percent per annum. The rate per annum is 

Nitin borrowed some money at the rate of 6% p.a. for the first three years, 9 % p. a. for the next five years and 13 % p.a. for the period beyond eight years. If the total interest paid by him at the end of eleven years is ₹8,160, the money borrowed by him ( in ₹ ) was -  

Megha invests an amount of Rs. 15,860 in the names of her three daughters A, B and C in such a way that they get the same interest after 2, 3 and 4 years respectively. If the rate of simple interest is 5 % p.a, then the ratio of the amounts invested among A, B and C will be – 

A person borrows some money for 5 years and the ratio of the loan amount: total interest amount is 5 : 2. Then find the ratio of the loan amount: interest rate is equal to