Subject: General Aptitude · Chapter: Problems on Ages · Exam: · Marks: · Difficulty:
The ages of Shakti and Kanti are in the ratio of 8 : 7 respectively. After 10 years, the ratio of their ages will be 13 : 12. What is the difference between their ages? (Bank P.O., 2008)
(a)2 years
(b)4 years
(c)8 years
(d)6 years
(e)None of these
Answer
Answer (as printed): A
Explanation
Let Shakti's age be $8x$ years. Then, Kanti's age $=7x$ years. $$\frac{8x+10}{7x+10}=\frac{13}{12} \Rightarrow 12(8x+10)=13(7x+10) \Rightarrow 96x+120=91x+130 \Rightarrow 5x=10 \Rightarrow x=2.$$ Difference between their ages $=(8x-7x)$ years $=x$ years $=2$ years.
Explanation as extracted from the printed page; notation may be imperfect.