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?

• A. 32 years
• B. 41 years
• C. 56 years
• D. 82 years

Answer 1

Answer:

B. 41 years

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