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

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.

The present age of Huang now = 9 years

Step-by-step 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

a is the right answer