A police jeep is following a car with 120m/s, fired on a car with 80m/s.if the car is moving with 170m/s,how fast will the bullet hit the car?.

Faster than the speed you will post your attempt it seems.

What.. :/

Basically, post your attempt.

I don't know its concept.. its just a trick I think..
total speed of bullet-object speed=final velocity of bullet
120+180-170=30 m/s.
please tell me how is it..

Yes, that's it!

But I must say that those cars are pretty fast and the bullets must be pretty large.