Question

In seven years, Huang will be two times as old as he was last year. How old is he now?

Answer 1

He's 9 years old. :-)

In seven years, he'll be 16, and 16 is two times older than 8 - the age he was last year.

Answer 2

The present age of Huang now = 9 years

Explanation:

Let the present age of Huang be x years

Now, after 7 years, Age of Huang will be : x + 7 years

Also, two times as old as he was last year = 2 × (x - 1)

These both quantities are given to be equal in the problem

So, Equating both these equations :

⇒ x + 7 = 2 × (x - 1)

⇒ x + 7 = 2x - 2

⇒ 2x - x = 7 + 2

⇒ x = 9

Hence, The present age of Huang now = 9 years