Question 1206003
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A brother is 3 years older than his sister, five years ago, the ratio of their ages {{{highlight(cross(were))}}} <U>was</U> 4:3.
Find their present ages
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<pre>
Let b be the brother's age 5 years ago.
Then the sister's age at that time was (b-3) years.


From the problem, we have this proportion

    {{{b/(b-3)}}} = {{{4/3}}}.


Cross multiply and find "b"

    3b = 4*(b-3)

    3b = 4b - 12

    12 = 4b - 3b

    12 =   b

     b = 12.


5 years ago the brother was 12 years old; the sister was 12-3 = 9 years old.

Hence, now the brother is 12+5 = 17 years old; the sister is 9+5 = 14 years old.    <U>ANSWER</U>
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Solved.