Difference between constant speed and average speed

If a body is traveling with constant speed, it means that it's distance is constantly increasing with time.

If it goes 5m in 3min, it will go 5m in next 3 min.

Average velocity is the total displacement divided by total time.

When the body travels 5m in 3 min and 25 m in next 3min, average velocity

= (25+5) / (3+3)

=30/6

=5m/min