Subject: General Aptitude · Chapter: Problems on Ages · Exam: 2010 · Marks: · Difficulty:
The ratio of the present ages of a mother and her daughter is 7 : 1. Four years ago, the ratio of their ages was 19 : 1. What will be the mother's age four years from now?
(a)42 years
(b)38 years
(c)46 years
(d)36 years
(e)None of these
Answer
Answer (as printed): C
Explanation
Let mother's age be $7 x$ years. Then, daughter's age $=x$ years. $\frac{7 x-4}{x-4}=\frac{19}{1}$ $$\begin{aligned} & \Rightarrow 7 x-4=19(x-4) \\ & \Rightarrow 19 x-7 x=76-4 \\ & \Rightarrow 12 x=72 \\ & \Rightarrow x=6 . \end{aligned}$$ Mother's age after 4 years $=(7 x+4)$ $$=(7 \times 6+4) \text { years }=46 \text { years. }$$
Explanation as extracted from the printed page; notation may be imperfect.