Arjun and Rajiv deposited Rs. 8400 and Rs. _____ in scheme A at 20% and at 10% per annum compound interest compounded annually, respectively. Also, Arjun and Rajiv deposited Rs. ____ and Rs. 3700 in scheme B at 15% and at 24% per annum simple interest, respectively. Sum of interest earned by both from both schemes together after 2 years is Rs. ____. The values given in which of the following options will fill the blanks in the same order in which is it given to make the statement true: I. 7200, 4120, 8220 II. 9600, 3640, 8540 III. 8000, 5400, 8772

Explanation

5 Detailed solution: Let, amount deposited by Rajiv in scheme A and Arjun in scheme B be Rs. x and Rs. y, respectively. Interest earned by Arjun from scheme A = 8400 × {(1.2)² – 1} = Rs. 3696 Interest earned by Rajiv from scheme A = x × {(1.)² – 1} = Rs. 0.21x Interest earned by Arjun from scheme B = y × 0.15 × 2 = Rs. 0.3y Interest earned by Rajiv from scheme B = 3700 × 0.24 × 2 = Rs. 1776 So, sum of interest earned by both of them = 3696 + 0.21x + 0.3y + 1776 = Rs. ‘5472 + 0.21x + 0.3y’ From option I: Sum of interest = ‘5472 + 0.21x + 0.3y’ = 5472 + 0.21 × 7200 + 0.3 × 4120 = 5472 + 1512 + 1236 = Rs. 8220 So, option I can be the answer. From option II: Sum of interest = ‘5472 + 0.21x + 0.3y’ = 5472 + 0.21 × 9600 + 0.3 × 3640 = 5472 + 2016 + 1092 = Rs. 8580 So, option II cannot be the answer. From option III: Sum of interest = ‘5472 + 0.21x + 0.3y’ = 5472 + 0.21 × 8000 + 0.3 × 5400 = 5472 + 1680 + 1620 = Rs. 8772 So, option III can be the answer.