Twenty years from now, Arjun will become three times as old as he is now. His present age is
Let Arjun be x years old now
After 20 years, his age will be x + 20
According to question,
x + 20 = 3x or 3x = x + 20
3x - x = 20
2x = 20
x = 10
Therefore, arjun's present age will be 10 yrs.