Madhya Pradesh Police Exam Model Paper 4

Given:
Age after 8 years = 3 × Present age
Concept used:
Using concept of linear equation.
Calculation:
Let the present age of man be x years
Let n years after the age will be 5 times of present age.
According to the question,
Age after 8 years = 3 × Present age
$\Rightarrow \mathit{x}+8=3\mathit{x}$
$\Rightarrow 2\mathit{x}=8$
$\Rightarrow \mathit{x}=4$
After n years = 5 × Present age
$\Rightarrow \mathit{x}+\mathit{n}=5\mathit{x}$
$\Rightarrow 4+\mathit{n}=20$
$\Rightarrow \mathit{n}=16$ years
∴ After 16 years the age will be 5 times of present age.