Question
Seven years ago, the ratio of the ages of A and B was 4:
5. Eight years hence, the ratio of the ages of A and B will be 9:10. What is the sum of their present ages in years?Solution
Seven years ago the ratio of ages of A and B = 4x : 5x Ratio of Present ages of A and B = 4x + 7 : 5x + 7 After 8 years the ratio of ages of A and B, ⇒ (4x + 7 + 8) : (5x + 7 + 8) = 9 : 10 ⇒ 40x + 150 = 45x + 135 ⇒ 5x = 15 ⇒ x = 3 Sum of present ages of A and B = (4 × 3 + 7) + (5 × 3 + 7) = 41 years ∴ The sum of present ages of A and B is 41 years.
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