a)
[tex]v = \frac{s}{t} \\ s = v \times t \\s = 3h \times 55 \frac{km}{h} \\ s = 165 km[/tex]
A
[tex]v = \frac{28km}{0.5h} = 56 \frac{km}{h} [/tex]
b)
[tex]165 - 58 = 107 \\ 165 + 28 + 107 = 300[/tex]
[tex]300km - x \\ 100km - 7l \\ 2100 = 100x \\ x = 21l[/tex]
[tex]1l - 5zl \\ 21l - x \\ x = 105zl[/tex]