How Do You Calculate a Car's Average Velocity?

[ariloz]

Homework Statement

A car starting from rest accelerates to the left. It takes 14 seconds to travel a distance of 20 meters. What is the car's average velocity?

I'm really confused by this question I'm not sure whether to use change in displament divided by change in time or (Velocity Initial + Velocity Final)/2?

Homework Equations

The Attempt at a Solution

 

[ariloz]

I just need to know what formula to use. Do you just divide 20 by 14 or do you do 1/2 times 0 + (whatever 20 divided by 14 is). So in other words...is 20/14 the average velocity or final velocity?

 

[Chandra Prayaga]

What is the definition of average velocity?