Question

At which condition velocity and speed will be equal?

Answer 1

Velocity will be equal to speed when the motion is linear that is when the object moves in only one direction.

Answer 2

Speed is something we measure every time in our instruments (like in bikes/cars) . It Simply says how fast the body is moving(distance covered/time). 
But velocity is displacement/time. Suppose you in morning you start for university and after spending all the day there you returned in evening . So displacement is finally 0. its just (final position - initial position ) . the path does not matter .
So i hope by this point you understand the fundamentals of velocity and speed. So We can say that if the body is moving in a linear path (straight highway) then  the average speed = average velocity.