 QUESTION

# 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. 3,508, what was the amount invested in scheme B?

Hint: To solve this question, we will let the amount invested in scheme B be x and then apply a formula of simple interest to find the amount.

Now, let the amount invested in B be Rs. x. Then, the amount invested in a is equal to Rs. (13,900 – x). The rate of interest per annum for A and B is 14% and 11% respectively. Now, simple interest is calculated by the formula,

Simple interest = $\dfrac{{{\text{P}} \times {\text{R}} \times {\text{T}}}}{{100}}$, where P is the principal amount invested, R is the rate of interest and T is the number of years.

According to question, S.I1 + S.I2 = 3508, where S.I1 is the simple interest earned by scheme A and S.I2 is the amount earned by B. So, applying the formula, we get

$\dfrac{{(13900{\text{ - x)(2)(14)}}}}{{100}}$ + $\dfrac{{({\text{x)(2)(11)}}}}{{100}}$ = 3508

14(13900 – x) + 11x = 175400

194600 – 14x + 11x = 175400

3x = 19200

x = 6400

So, amount invested in scheme B = Rs. x = Rs. 6400

Note: When we come up with such types of questions, we will first let the value be found as a variable. Then we will use the formula to find simple interest. Then, we will apply the values given in question in the formula. After it, we will solve the formed equation to find the value of the variable which is our required answer.