On an appropriate set of axes, draw the line d = 350 t (where has the 350 come from?) but stop at a point. Label that point (d1, t1). t1 is the time flown with the wind. What is the relationship between d1 and t1 (you will need this relationship)?
Now draw a line from the point (d1, t1) to the point (0, 4) (where has the 4 come from?) What must the slope of this line be? Use the value of this slope to help calculate a value of t1.
Hence answer question 2.