Answer
a) scalar
b) vector
c) vector
d) scalar
Work Step by Step
(a) The cost of a ticket has no direction as required to be a vector.
(b) The current has a magnitude, the force of the river, and a direction, it's path of travel.
(c) The flight path includes a velocity and direction of travel.
(d) The population of the world doesn't qualify as a vector as it has no direction.
