The correct answer is half of the sum of initial and final velocity.

 Key Points

• The rate of change of velocity of an object is constant. Its average velocity is half of the sum of initial and final velocity.
• The average velocity of an object is its total displacement divided by the total time taken. In other words, it is the rate at which an object changes its position from one location to another.
• A vector quantity is a average velocity. Meters per second is the SI unit. However, if appropriate, any unit of distance can be used for each unit of time, such as miles per hour (mph) or kilometers per hour (km/h).
• Average velocity: The ratio of net displacement to the total time taken is called the average velocity.

\(Average\;velocity\;\left( {V_{av}} \right) = \frac{{{\rm{Net\;displacement\;}}\left( {{\rm{S}}} \right)}}{{time\;taken\;\left( t \right)}}\)

Average velocity is also given by:

Vav = (u + v) / 2

where u is the initial velocity and v is the final velocity of the object.