Erica walked from home to a friend's house, watched TV for a while, then walked back home. Which is the correct graph when y = Erica's distance from home?

Erica walked from home to a friend's house, watched TV for a while, then walked back home. Which is the correct graph when

y = Erica's speed?

As our subway train leaves Station A, it accelerates to top speed. It maintains top speed until it begins to slow down and finally stop at Station B. Which is the correct graph when

y = distance from Station A?

A backpacker hikes toward a campsite at a steady rate until he stops for a while to rest. Then he continues at the original rate of speed until he reaches the campsite. Which is the correct graph when

y = distance from the campsite?

Roy rode his bike at a slow but steady speed, then went faster and faster as he rode down the other side.

x = time, y = distance traveled