SOLUTION: At 6 A.M. a snowplow, traveling at a constant speed, begins to clear a highway leading out of town. At 8 A.M. an automobile begins traveling the highway at a speed of 20 mi/hr and

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Question 707007: At 6 A.M. a snowplow, traveling at a constant speed, begins to clear a highway leading out of town. At 8 A.M. an automobile begins traveling the highway at a speed of 20 mi/hr and reaches the plow 40 minutes later. Find the speed of the snowplow.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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At 6 A.M. a snowplow, traveling at a constant speed, begins to clear a highway leading out of town.
At 8 A.M. an automobile begins traveling the highway at a speed of 20 mi/hr and reaches the plow 40 minutes later. Find the speed of the snowplow.
:
Let s = the speed of the snowplow
:
Change 40 min to hrs: 40/60 = 2%2F3 hr is the travel time of the car
and
22%2F3 or 8%2F3 hrs is the travel time of the snowplow
:
When the car overtakes the snowplow they will have traveled the same distance.
Write a distance equation; dist = speed * time
:
car dist = snowplow dist
20*2%2F3 = 8%2F3s
40%2F3 = 8%2F3s
multiply both sides by 3, get rid of the denominators
40 = 8s
s = 40/8
s = 5 mph is the speed of the snowplow
:
:
Confirm this by finding the actual distance each traveled, should be the same.
decimals will be close enough to check it
.67*20 = 13.4 mi
2.67*5 ~ 13.4 mi