2018 · Q37
Ten (10) years before, the ages of a mother and her daughter were in the ratio 3 : 1. In another 10 years from now, the ratio of their . ages will be 13 : 7. What are their present ages ?
Elementary MathematicsRatio and Proportion
- A39 years, 21 years
- B55 years, 25 years
- C75 years, 25 years
- D49 years, 31 years
Explanation
Ten years ago the ages were 3x and x; in ten years they will be 3x + 20 and x + 20, with (3x + 20)/(x + 20) = 13/7. Solving: 21x + 140 = 13x + 260, so x = 15. The present ages are 3 x 15 + 10 = 55 and 15 + 10 = 25. Hence option B.