A car travels 50kms east, 40kms north, 20kms west. This journey takes two hours what is his velocity in m/sec?

Firstly, he doesn't have a single velocity because he keeps changing direction.

Do you want the average velocity over the two hours?

Then you need to work out the total displacement by using pythagoras or trigonometry.

How many seconds is 2 hours?

Therefore what is his average velocity.