Please, this is an emergency

A girl is riding a bicycle at a constant velocity of 3.0 m/s along a straight road. At time t=0, she passes a boy sitting on a stationary bicycle. At time t=0, the boy sets off to catch up with the girl. His velocity increases from time t=0 until t=5.0s, when he has converted a distance of 10m. He then continues at a constant velocity of 4m/s.

a. Draw the displacement-time graph for the girl from t=0 to 12s
b. On the same graph axes, draw the displacement-time graph for the boy
c. Using your graph, determine the value of t when the boy catches up with the girl.