Question: Joe’s present age is $ \frac{2}{7},th $ of his father’s present age. Joe’s brother is 3 yr older to Joe. The respective ratio between present ages of Joe’s father and Joe’s brother is 14: 5. What is Joe’s present age? [SBI (PO) Pre 2015]
Options:
A) 6 yr
B) 15 yr
C) 12 yr
D) 18 yr
E) 20 yr
Show Answer
Answer:
Correct Answer: C
Solution:
- Let the Joe’s father present age = x yr
Joe’s present age $ =\frac{2}{7}x $
Joe’s elder brother present age $ =\frac{2}{7}x+3,yr $
According to the question,
$ \frac{x}{3+\frac{2}{7}x}=\frac{14}{5} $
$ \Rightarrow $ $ 5x=14,( 3+\frac{2}{7}x ) $
$ \Rightarrow $ $ 5x=42+4x $
$ \Rightarrow $ $ 5x-4x=42 $
$ \Rightarrow $ $ x=42yr $
Joe’s present age $ =\frac{2}{7}x=\frac{2}{7}\times 42=2\times 6=12yr $