Question

    An amount is invested at a compound interest rate of 21%

    per annum, with compounding occurring once every 10 months. After 20 months, the interest earned on the investment is ₹1,827. Determine the principal amount that was initially invested.
    A Rs. 5,600 Correct Answer Incorrect Answer
    B Rs. 5,400 Correct Answer Incorrect Answer
    C Rs. 4,800 Correct Answer Incorrect Answer
    D Rs. 4,400 Correct Answer Incorrect Answer

    Solution

    Number of times the interest is compounded = 20 ÷ 10 = 2 Rate of interest = 21 X (10/12) = 17.5% Let the sum invested = Rs. 'Y' Then, Y X {1 + (17.5/100)}2 - Y = 1827 Or, Y X (47/40)2 - Y = 1827 So, (609Y/1600) = 1827 So, Y = (1827/609) X 1600 = 4800 So, sum invested = Rs. 4,800

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