Question
A’s present age is double B’s present age. After 6
years, A’s age will be four times the present age of C. The ratio of B’s age 3 years ago to C’s age 1 year hence is 2:3. If D’s present age is three times A’s present age, find D’s present age.Solution
ATQ, Let, the present age of B = x years So, the present age of A = 2x years Let, the present age of C = y years After 6 years, A’s age will be four times the present age of C 2x + 6 = 4y y = (2x + 6)/4 y = (x + 3)/2 Given ratio: (B’s age 3 years ago) : (C’s age 1 year hence) = 2 : 3 (x - 3)/(y + 1) = 2/3 (x - 3)/((x + 3)/2 + 1) = 2/3 (x - 3)/((x + 3 + 2)/2) = 2/3 (x - 3)/((x + 5)/2) = 2/3 2(x - 3)/(x + 5) = 2/3 6(x - 3) = 2(x + 5) 6x - 18 = 2x + 10 4x = 28 x = 7 Present age of A = 2x = 14 years Present age of D = 3*(Age of A) = 3*14 = 42 years
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