In a pie-chart, an angle of 30° represents 80 articles. The number of articles represented by 105° are :

1. 280

2. $22\dfrac{6}{7}$

3. 200

4. none of these

It is given that an angle of 30° represents 80 articles.

Therefore, the number of articles represented by an angle of 1° is:

= $\dfrac{80}{30}$ articles = $\dfrac{8}{3}$ articles

The number of articles represented by an angle of 105° is:

= $\dfrac{8}{3} \times 105$ articles.

= $\dfrac{840}{3}$

= 280 articles

Hence, option 1 is the correct option.