Question

can a body have a constant velocity and still have varying speed? explain with an example

Answer 1

Nope,
Varying speed without varying velocity is meaningless statement.

Speed is magnitude of velocity.Since velocity is vector it has both magnitude as well as direction.Change in any of magnitude or direction will change velocity.

However,Varying velocity without varying speed is ofcourse possible if we change the direction only keeping magnitude of velocity that is Speed constant or same.

Answer 2

If velocity is there then there will be a constant speed also as constant velocity means that we are time and distaplacement are equal and speed means distance and time are equal.
displacement can be said as distance in the speed case