Question
The ratio of the ages of A and B is 3:5. After 5 years,
the ratio will be 7:11. Find the present age of B.Solution
Let the present ages of A and B be 3x and 5x, respectively. After 5 years, the ages will be 3x + 5 and 5x + 5. The new ratio is given as (3x + 5) / (5x + 5) = 7/11. Cross-multiply: 11(3x + 5) = 7(5x + 5) 33x + 55 = 35x + 35 2x = 20 x = 10 Now, the present age of B = 5x = 5 × 10 = 50






