Question

    Rs. 6000 when invested at simple interest of r% p.a.

    amounts to Rs. 9000 in 24 months. If the same sum had been invested for 1 year at compound interest of (r + 20) % p.a. (compounded in every 4 months), then the amount received would be?
    A 9125.25 Correct Answer Incorrect Answer
    B 9025.25 Correct Answer Incorrect Answer
    C 9105.25 Correct Answer Incorrect Answer
    D 9120.25 Correct Answer Incorrect Answer

    Solution

    According to the question, 9000 – 6000 = (6000 × r × 24) ÷ (12 × 100) Or, 3000 = 120 × r Or, r = 25 When the sum is invested at compound interest, Effective rate of interest = (r + 20) ÷ 3 = (25 + 20) ÷ 3 = 15% Effective time period = 1 × 3 = 3 units Amount received = Principal × {1 + (r/100)}time period = 6000 × {1 + (15/100)}3 = 6000 × (1.15)3 = 9125.25

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