The sum of the present ages of a father and his son is 78 years. After five years, the ratio of their ages becomes 7 : 4. What is the present age (in years) of the father?
Show answer & explanation
Correct answer: B
Explanation
Correct Answer is option 2 i.e. 51
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Understanding |
Application |
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The sum of the present ages of a father and his son is 78 years |
Suppose Present Age of father = x Present Age of Son = y So, x + y = 78 ………(1) |
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After five years, the ratio of their ages becomes 7 : 4. |
So, (x + 5)/(y + 5) = 7/4 ⇒ 4x + 20 = 7y + 35 ⇒ 4x – 7y = 15 ......(2) |
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Solving both equations. |
Multiply 1st equation by 7 and add both: ⇒ 11x = 561 ⇒ x = 51 And y = 78 – 51 = 27 |
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Hence, Present age of the father = 51 years |