How can vectors be used in real life?

Using vectors can be troublesome for simple physics problems. however, when you move onto solving more difficult problems that have several variables, and the space you are dealing with is in three dimensions, using vectors is a necessity because it's not always possible to visualize the problem. but using vectors will give you a definitive answer.

few applications of vectors:
-predict the trajectory of airplanes and make sure that the airplane will not collide with some other airplane
-all simulations use vectors
-multivariable Calculus is pretty much based on vectors. without multivariable Calculus, it would have not been possible to compute many formulas.
-modeling the path a rocket will take, and supplying it the right amount of fuel so that it gets to the moon, or some other destination.

The answer would be a