$C1: C$
$C2: B$
$C3: B$
$C4: A$
$C5: C$
$C6: C$
→ $2km = 2000m$ ║ $10ph = 600s$
⇒ $v=\frac{s}{t} => $ $\frac{2000}{600} = $ $\frac{10}{3} = 3.33(m/s)$
$C7: D $
→ $1m/s = 3.6km/h$
⇒ $v=\frac{s}{t} =>t= $ $\frac{s}{v} = $ $\frac{7,2}{3,6} = 2(h)$
$@JULLY$