Bhavani invested an amount of Rs. 13900 divided in two different schemes, A and B at the simple interest rate of 14% per annum and 11% per annum respectively if the total amount of simple interest earned in two year be Rs. 3508, what was the amount invested in Scheme B?

Let the amount invested in scheme A be 'P'. Hence, amount invested in scheme B would be '13900-P' .

In scheme A , as the interest rate is 14% per annum , for 2 years the interest = $$\dfrac{\ P\times\ 2\times\ 14}{100}$$ 
In scheme B, as the interest rate is 11% per annum, for 2 years the interest =  $$\left((13,900-P\right)\times\ 2\times\frac{\ 11}{100}$$

total interest = $$\dfrac{\ 22\left(13,900\right)-4P}{100}$$ = 3508 
Therefore, upon solving the above, we arrive at P = 7500.
Hence, amount invested in B = 13900-7500 = 6400