Question

    The difference between total SI earned on Rs 'P' at 18% p.a. for 3 years and total CI earned on same sum at 20% p.a. for 2 years when compounded annually is Rs 640. Find P? (in Rs.)

    A Rs. 6500 Correct Answer Incorrect Answer
    B Rs. 6420 Correct Answer Incorrect Answer
    C Rs. 6400 Correct Answer Incorrect Answer
    D Rs. 6550 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    SI = (P × 18 × 3)/100 = 54P/100 CI = P{(1 + 20/100)2 – 1} = 44P/100 ATQ, 54P/100 – 44P/100 = 640 10P/100 = 640 P = Rs. 6400 Alternate Method: Total interest when calculated as SI = 18% × 3 = 54% Total interest when calculated as CI = 20 + 20 + (20 × 20)/100 = 44% ATQ: 54% - 44% = 640 1% = 64 100% = 6400 Therefore, P = Rs. 6400

    Practice Next

    Relevant for Exams: