5 years ago, the age of mother and her daughter was in ratio 3 : 1. 15 years hence, the ratio of their ages will be 13 : 7. What are their present ages ?
Answer & explanation
Correct answer: option 2
5 years ago:⇒ Age of mother : age of daughter = 3 : 1
15 years hence:⇒ Age of mother : age of daughter = (3R + 20) : (1R + 20)
Now, ATQ
⇒ \(\frac{3R\;+\;20}{1R\;+\;20}\) = \(\frac{13}{7}\)
⇒ 21R + 140 = 13R + 260
⇒ 8R = 120
⇒ 1R = 15
So,
Mother's present age = 3R + 5 = (15 × 3) + 5 = 45 + 5 = 50
Daughter's present age = 1R + 5 = (15 × 1) + 5 = 20