A chipmunk, trying to cross a road, first moves 80 cm to the right, then 30 cm

Question:

A chipmunk, trying to cross a road, first moves 80 cm to the right, then 30 cm to the left, then 90 cm to the right, and finally 310 cm to the left.
(a) What is the chipmunk's total displacement?
(b) If the elapsed time was 18 s, what was the chipmunk's average speed?
(c) What was its average velocity?