Question
Present ages of ‘A’, ‘B’ and ‘C’ are in the
ratio 8:9:12, respectively. If present average age of ‘A’ and ‘C’ is 20 years, then find the age of ‘B’ when ‘C’ was 20 years old?Solution
Let the present ages of ‘A’, ‘B’ and ‘C’ be ‘8x’ years, ‘9x’ years and ‘12x’ years, respectively. ATQ; (12x + 8x) ÷ 2 = 20 Or, 20x = 40 So, x = 2 So, present age of ‘C’ = 12 × 2 = 24 years Present age of ‘B’ = 9 × 2 = 18 years Difference between the ages of ‘B’ and ‘C’ = 24 – 18 = 6 years So, age of ‘B’ when ‘C’ was 20 years old = 20 – 6 = 14 years
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