SOLUTION: A ship cruising on a river can travel the 135 mile distance between two cities in 15 hours when cruising against the current. When cruising with the current, the trip takes 5 fewe

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Question 132505This question is from textbook Holt Algebra 1
: A ship cruising on a river can travel the 135 mile distance between two cities in 15 hours when cruising against the current. When cruising with the current, the trip takes 5 fewer hours. Write and solve a system of equations to find the speed of the current and of the ship in still water. This question is from textbook Holt Algebra 1

Found 2 solutions by checkley71, stanbon:
Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website!
135/15=9 mph. for the trip upstream.
135/(15-4)=135/11=12.27 mph. for the trip downstream.
(12.27-9)/2=3.27/2=1.64 mph. for the current.
9+1.64=10.64 mph. for the boat ibn still water.
12.27-1.64=10.64 mph for the boat.

Answer by stanbon(75887) (Show Source):
You can put this solution on YOUR website!
A ship cruising on a river can travel the 135 mile distance between two cities in 15 hours when cruising against the current. When cruising with the current, the trip takes 5 fewer hours. Write and solve a system of equations to find the speed of the current and of the ship in still water.
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Upstream DATA:
Distance = 135 miles ; time = 15 hrs. ; rate = 135/15 = 9 mph
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Downstream DATA:
Distance = 135 miles ; time = 10 hrs. ; rate = 135/10 = 13.5 mph
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Let current speed be "c"; Let boat speed be "b".
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EQUATIONSL
b+c = 13.5
b-c = 9
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Add to solve for "b":
2b = 22.5
b = 11.25 mph (boat speed in still water)
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Substitute to solve for "c":
11.25 + c = 13.5
c = 2.25 mph (current speed)
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Cheers,
Stan H.