Question
At present, A is thrice as old as B. C is 5 years elder
than B. The sum of the ages of A, B, C is 75 years. The ratio of the age of B five years ago to the age of A three years from now is:Solution
Let B's age be x. Then, A's age = 3x, and C's age = x + 5. Given: 3x + x + (x + 5) = 75 5x + 5 = 75 5x = 70 ⟹ x=14 A's age = 3 × 14 = 42 yrs B's age = 14 yrs C's age = 14 + 5 = 19 yrs Five years ago, B's age = 14 − 5 = 9 Three years from now, A's age = 42 + 3 = 45 Required ratio = 9/45 = 1/ 5
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