Answer:
Part A. At least 6 hours
Part B. In less than 2.5 hours Elijah will be behind Mercedes
Part C. In more than 2.5 hours Elijah will be ahead Aubrey
Step-by-step explanation:
D = distance
v =speed
t = time
Formula connecting D, v and t:
Part A.
Steve's speed:
Distance: at least 21 miles
Time: unknown, so
It would take Steve at least 6 hours to walk at least 21 mi on Day 1.
Part B.
Mercedes's speed:
Elijan's speed:
Elijan's Distance walked: miles
Mercedes's Distance walked: miles
Time: x hours
Mercedes is 2 miles ahead, so
Elijan will be behind when
In 2.5 hours Elijan will catch up Mercedes, and in less than 2.5 hours Elijah will be behind Mercedes.
Part C.
Aubrey's speed:
Elijan's speed:
Elijan's Distance walked: miles
Aubrey's Distance walked: miles
Time: x hours
At the beginning of Day 3, Elijah starts walking at the marker for Mile 42, and Aubrey starts walking at the marker for Mile 42.5.
Elijan will be ahead of Aubrey when
In 2.5 hours Elijan will catch up Aubrey, and in more than 2.5 hours Elijah will be ahead Aubrey.