Subject: General Aptitude · Chapter: Ratio and Proportion · Exam: · Marks: · Difficulty:
Aruna is twice as old as Sneha. What is the difference in their ages? I. Five years hence, the ratio of their ages would be 9 : 5. II. Ten years back, the ratio of their ages was 3 : 1.
Answer
SELF-PRACTICE — the source book printed no answer.
Nothing is invented here, so this question has no answer on record.
Explanation
Let the present ages of Sneha and Aruna be $x$ and $2x$ years respectively. I. $\frac{2x+5}{x+5}=\frac{9}{5} \Rightarrow 5(2x+5)=9(x+5) \Rightarrow x=20$. So, required difference $=2x-x=x=20$ years. II. $\frac{2x-10}{x-10}=\frac{3}{1} \Rightarrow 2x-10=3(x-10) \Rightarrow 2x-10=3x-30 \Rightarrow x=20$. So, required difference $=20$ years. Thus, either I alone or II alone gives the answer. $\therefore$ Correct answer is (c).
Explanation as extracted from the printed page; notation may be imperfect.