Mr. Thomas invested an amount of Rs. 13,900 divided in two different schemes A and B at the simple interest rate of 14% p.a. and 11% p.a. respectively. If the total amount of simple interest earned in 2 years be Rs. 3508, what was the amount invested in Scheme B?

Answer: Option A

Let the sum invested in Scheme A be Rs. x and that in Scheme B be Rs. (13900 - x)
Then,
$$\frac{x\times 14\times 2}{100}+$$   $$\frac{\left(13900-x\right)\times 11\times 2}{100}$$     $$=3508$$
⇒ 28x - 22x = 350800 - (13900 x 22)
⇒ 6x = 45000
⇒ x = 7500
So, sum invested in Scheme B
= Rs. (13900 - 7500)
= Rs. 6400