Question

The waiter places a bowl of soup in front of Igor. In a counterclockwise direction, he passes the soup to Elan who then passes it to Abbey. Which two rotations about the center of the table describe passing the soup?
A) first 80° and then 80°
B) first 120° and then 120°
C) first 144° and then 144°
D) first 160° and then 160°

Answer 1

$\alpha=\frac{360^o}{12}=30^o\\\\Igor-Elan\to4\cdot30^o=120^o\\\\Elan-Abbey\to4\cdot30^o=120^o\\\\Answer:C$