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    Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7. If the product of their present ages is 616, find the ratio of their present age
    Question

    Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7. If the product of their present ages is 616, find the ratio of their present age.

    A.

    12 : 13

    B.

    11 : 14

    C.

    15 : 17

    D.

    17 : 15

    Correct option is B

    Seven years ago, the ratio of the ages of Ajith and Ganesh was 5 : 7.
    Let their ages be measure in terms of x, then their present ages are 5x + 7 and 7x + 7 respectively.
    If the product of their present ages is 616,
    Then (5x+7) (7x+7) = 616
    35x2^2​ + 35 x + 49x + 49 = 616
    35x2^2 + 84x + 49-616 = 0 ​
    35x2^2 +84x-567 = 0 ​
    =>7(5x2^2 + 12x-81) = 0 ​
    →5x2^2 + 12x81 = 0 ​
    = 5x2^2 + (27 – 15)x – 81 = 0 ​
    5x2^2+ 27x-15x - 81 = 0 ​
    = x (5x + 27) – 3(5x + 27) = 0
    = (5x + 27) (x – 3) = 0
    =>x=-27/5 or, x = 3

    putting the value of x in 5x + 7 and 7x + 7

                                        =22:28

                                          =11:14

    ratio of their present age = 11:14

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