SOLUTION: aaron and jessica walk to the dock at 2 miles per hour,jumped into the boat, and motored to denver at 46 miles per hour. If the toatal distance was 21 miles and the trip took 5 hou

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Question 467408: aaron and jessica walk to the dock at 2 miles per hour,jumped into the boat, and motored to denver at 46 miles per hour. If the toatal distance was 21 miles and the trip took 5 hours in all, how far did they go by boat?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
aaron and jessica walk to the dock at 2 miles per hour,jumped into the boat,
and motored to denver at 46 miles per hour.
If the total distance was 21 miles, and the trip took 5 hours in all, how far did they go by boat?
:
Let b = distance traveled by boat
then, since the total dist was 21 mi, we can say:
(21-b) = distance walked
:
Write a time equation, time = dist/speed
walk time + boat travel time = 5 hrs
%28%2821-b%29%29%2F2 + b%2F46 = 5
we can clear the denominators by multiplying by 46, results:
23(21-b) + b = 46(5)
483 - 23b + b = 230
-23b + b = 230 - 483
-22b = -253
b = 253%2F22
b = 11.5 mi by boat
:
:
Check this, 21 - 11.5 = 9.5 mi walking
Walk time: 9.5/2 = 4.75 hrs
Boat time: 11.5/46 = .25 hrs
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total travel time: 5 hrs