I have tried to answer this question for a while... I really dont understand it!! can someone help me? THANKS!

A car of mass 900kg was travelling at 30m/s when a small child ran in front of the car. the drivers reaction time was 0.2s and it takes a furth 2s to bring the car to a stop. calculate:
a) the 'thinking distance' travelling by the car during the reaction time.
b) the braking deceleration.
c) the average breaking force