Answer:
[tex]a \\ \frac{50}{0.25} = 200 \: \frac{km}{ {h}^{2} } \\ b \\ the \: area \: under \: graph = whole \: distance = \\ = 50 \times (2 + 1.5) \times 0.5 + \\ + 50 \times (0.5 + 1) \times 0.5 = 125km \\ c \\ \ \: average \: speed \: = \frac{125}{2} = 62.5 \frac{km}{h} [/tex]
