The accelaration of the vehicle?

In an accident investigation, police measured the skid marks left by a vehicle. They measure the skid marks to be 150m from the point where the driver applied the brakes to where the car came to rest. In their investigation, the police umed that the driver was travelling at the speed limit of 80km/h (22m/s) when the brakes were applied. Calculate the accelaration of the vehicle.