A blue car travelling at 8 0 km / - 1 west is passed by a red car travelling in the same direction at

 

$$A blue car travelling at $80$ km$/ℎ^-\mathrm{¹}$west is passed by a red car travelling in the same direction at $100$ km$/ℎ$^-1.

$-$ What is the velocity of the red car relative to the blue car?

$-$ What is the velocity of the blue car relative to the red car?

A green car then passes the blue car. The velocity of the green car relative to the blue car is $6$ km$/ℎ$^-1west.

$-$ What is the velocity of the green car?

$-$ What is the velocity of the green car relative to the red car?