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    Question

    The ratio of the ages of A and B is 3:4. Five years

    later, the ratio of their ages will be 4:5. What are their present ages?
    A A is 15 years, B is 20 years Correct Answer Incorrect Answer
    B A is 18 years, B is 24 years Correct Answer Incorrect Answer
    C A is 21 years, B is 28 years Correct Answer Incorrect Answer
    D A is 24 years, B is 32 years Correct Answer Incorrect Answer

    Solution

    Let the present ages of A and B be 3x and 4x, respectively. After 5 years: Age of A = 3x + 5 Age of B = 4x + 5 According to the problem: (3x + 5) / (4x + 5) = 4/5 Cross-multiplying gives: 5(3x + 5) = 4(4x + 5) 15x + 25 = 16x + 20 15x - 16x = 20 - 25 -x = -5 => x = 5 Present Ages: Age of A = 3x = 3(5) = 15 years Age of B = 4x = 4(5) = 20 years Correct Answer: a) A is 15 years, B is 20 years.

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