Option C.
Step-by-step explanation:
Let x be the unknown number.
Some number divided by 3 ⇒ ![\frac{x}{3}](/tpl/images/0357/2636/80715.png)
8, minus some number divided by 3 ⇒ ![8-\frac{x}{3}](/tpl/images/0357/2636/7b0f0.png)
It is given that 8, minus some number divided by 3, equals 6.
So, the given equation is
![8-\frac{x}{3}=6](/tpl/images/0357/2636/41a82.png)
Subtract 8 from both sides.
![-\frac{x}{3}=6-8](/tpl/images/0357/2636/d99b3.png)
![-\frac{x}{3}=-2](/tpl/images/0357/2636/94e1d.png)
Multiply both sides by -3.
![x=6](/tpl/images/0357/2636/bdba1.png)
The value of unknown number is 6. Therefore, the correct option is C.