An engineer must regularly inspect the horn of the Coast City Coach's commuter train. The
train can travel at most 300 hours between these inspections.
This table shows the travel times for Coast City Coach's commuter train:
Coast City Coach's schedule
Departure Time
Train
Coast City Coach, eastbound
Coast City Coach, westbound
7:00a.m.
2:30 p.m.
The train has already traveled for 125 hours since the last time its horn was inspected. The
engineer wants to know how many more round trips the train can travel until its horn must
be inspected again.
This problem can be solved with an inequality that uses the variable x.
How should x be defined?
x= the number of round trips until the next inspection
x = the number of hours for a round trip
x= the distance the train travels in a round trip
Which inequality can be used to find x?
12.5x < 300
x= the number of round trips since the last inspection
6.5x+125 ≤ 6x + 300
Arrival Time
1:00 p.m.
9:00 p.m.
12.5x425
12.5x+125 s 300