Level:
Project ID:
1003055104
Source Problem:
Accepted:
1
Clonable:
1
Easy:
1
The measures of given angles belong to the set \( M \):
\[ M = \left\{ 120^{\circ} + k\,360^{\circ}\right\},\ k\in\{-1;0;1\}.\]
Determine their arithmetic mean.
\( 120^{\circ} \)
\( 420^{\circ} \)
\( -120^{\circ} \)
\( -420^{\circ} \)