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Six years ago, the ratio of the ages of Ramesh and Sundar was 6 : 5. Four years hence, the ratio of their ages will be 11 : 10. What is the present age of Sundar?1. 16 years2. 20 years3. 18 years4. None of the above |
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Answer» Correct Answer - Option 1 : 16 years Given Six years ago, the ratio of the ages of Ramesh and Sundar was 6 : 5 Four years hence, the ratio of their ages will be 11 : 10 Calculation Let present age of Ramesh is x years and Present age of Sundar is y years Now, Six year ago age of Ramesh and Sundar ⇒ Ramesh age six year ago = (x - 6) years ⇒ Sundar age six year ago = (y - 6) years From question ⇒ (x - 6) ∶ (y - 6) = 6 ∶ 5 ⇒ (x - 6)/(y - 6) = (6/5) ⇒ 5x - 30 = 6y - 36 ⇒ 6y - 5x = 6 ....(1) Now, four years hence ⇒ Ramesh age four years hence = (x + 4) ⇒ Sundar age four years hence = (y + 4) From question ⇒ (x + 4) ∶ (y + 4) =11 ∶ 10 ⇒ (x + 4)/(y + 4) = 11/10 ⇒ 10x + 40 = 11y + 44 ⇒ 10x - 11y = 4 ....(2) Multiply equation (1) on both side by 2 ⇒ (6y - 5x = 6) × 2 ⇒ 12y - 10x = 12 ....(3) Now add equation (2) and equation (3) ⇒ 10x - 11y + 12y - 10x = 12 + 4 ⇒ y = 16 ⇒ Sundar present age = 16 years ∴ Sundar present age = 16 years |
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