Aman’s age is three times his son’s age. Ten years ago, he was five times his son’s age. Find their present ages.

Let the age of Aman’s son = $x$, then the age of Aman = $3x$.  

According to the question:

$5(x - 10) = 3x - 10$
$\Rightarrow 5x - 50 = 3x - 10$
$\Rightarrow 5x - 3x = -10 + 50$
$\Rightarrow 2x = 40$
$\Rightarrow x = 20$

Aman’s son age = $x = 20$ years  
Aman’s age = $3x = 3 \times 20 = 60$ years

मान लीजिए अमन के पुत्र की आयु = $x$, तब अमन की आयु = $3x$।  

प्रश्न के अनुसार:

$5(x - 10) = 3x - 10$
$\Rightarrow 5x - 50 = 3x - 10$
$\Rightarrow 5x - 3x = -10 + 50$
$\Rightarrow 2x = 40$
$\Rightarrow x = 20$

अमन के पुत्र की आयु = $x = 20$ वर्ष  
अमन की आयु = $3x = 3 \times 20 = 60$ वर्ष