You and your friends are hiking in the woods. In the morning you travel 30$\mathrm{}\mathrm{}$km in 4.5$\mathrm{}\mathrm{}\mathrm{}$ hours. After lunch you turn back and arrive at your starting point after walking an additional 7$\mathrm{}$ hours. 

 

A)$)$ what are your speeds before and after lunch?

B)$)$ what is your average speed the entire journey

C)$)$ what is your average velocity for the entire journey