In Exercises 17–20, find the rate on the basis of the information provided. Use a calculator
and round your answers to the nearest hundredth. All events were at the 2008 Summer
Olympics in Beijing, China. (Source: World Almanac and Book of Facts.)
86 CHAPTER 2 Linear Equations, Inequalities, and Applications
Solve each problem. See Examples 2 and 3.
Event Participant Distance Time
- 100-m hurdles, women Dawn Harper, USA 100 m 12.54 sec
- 400-m hurdles, women Melanie Walker, Jamaica 400 m 52.64 sec
- 400-m hurdles, men Angelo Taylor, USA 400 m 47.25 sec
- 400-m run, men LaShawn Merritt, USA 400 m 43.75 sec
21.Two steamers leave a port on a river at
the same time, traveling in opposite di-
rections. Each is traveling 22 mph. How
long will it take for them to be 110 mi
apart?
22.A train leaves Kansas City, Kansas, and
travels north at 85 km per hr. Another
train leaves at the same time and travels
south at 95 km per hr. How long will it
take before they are 315 km apart?
Rate Time Distance
First Train 85 t
Second Train
315
Rate Time Distance
First Steamer t
Second Steamer 22
110
23.Mulder and Scully are driving to Georgia
to investigate “Big Blue,” a giant reptile
reported in one of the local lakes. Mulder
leaves the office at 8:30 A.M. averaging
65 mph. Scully leaves at 9:00 A.M., fol-
lowing the same path and averaging
68 mph. At what time will Scully catch
up with Mulder?
24.Lois and Clark, two elderly reporters,
are covering separate stories and have to
travel in opposite directions. Lois leaves
the Daily Planetbuilding at 8:00 A.M.
and travels at 35 mph. Clark leaves at
8:15 A.M. and travels at 40 mph. At what
time will they be 140 mi apart?
Rate Time Distance
Mulder
Scully
Rate Time Distance
Lois
Clark
- It took Charmaine 3.6 hr to drive to her mother’s
house on Saturday morning for a weekend visit.
On her return trip on Sunday night, traffic was
heavier, so the trip took her 4 hr. Her average rate
on Sunday was 5 mph slower than on Saturday.
What was her average rate on Sunday?
26.Sharon Kobrin commutes to her office by train.
When she walks to the train station, it takes her
40 min. When she rides her bike, it takes her
12 min. Her average walking rate is 7 mph less
than her average biking rate. Find the distance
from her house to the train station.
27.Johnny leaves Memphis to visit his cousin, Anne Hoffman, who lives in the town of
Hornsby, Tennessee, 80 mi away. He travels at an average rate of 50 mph. One-half hour
later, Anne leaves to visit Johnny, traveling at an average rate of 60 mph. How long after
Anne leaves will it be before they meet?
28.On an automobile trip, Laura Iossi maintained a steady rate for the first two hours. Rush-
hour traffic slowed her rate by 25 mph for the last part of the trip. The entire trip, a distance
of 125 mi, took 2 12 hr. What was her rate during the first part of the trip?
Rate Time Distance
Saturday
Sunday
Rate Time Distance
Walking
Biking
