A person travels x distance with velocity v1 and then x distance with velocity v2 in the same direction. The average velocity of the person is v, then the relation between v, v1, and v2 will be
a. v = (v1 + v2) / 2
b. v = v1 + v2
c. v = 2v1 + v2
d. v = v1 - v2
