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A boat traveled 126 miles downstream and back. The trip downstream took 6 hours. The trip back took 42 hours. What is the speed of the boat in still water? What is the speed of the current?

Respuesta :

Answer:

The answer is

Speed of the boat in still water= 12mph

Speed of current= 9mph

Step-by-step explanation:

let x= speed of the boat in still water

let y= speed of current

DATA WE HAVE

with current  

rate- x+y        

time- 6 hours

distance- 126 miles

rate= 126/6= 21

against current

rate- x-y

time- 42hr

distance- 126 miles

126/42= 3

Now, we add these two equations vertically.

x-y=3

+

x+y=21            

2x = 24

Now we divide each side by 2

2x/2   24/2

x= 12

The speed of the boat in still water is 12mph

NOW WE HAVE HALF OF THE ANSWER

if x+y= 21

then

12+y=21

subtract 12 from both sides

y=9

The speed of the current is 9mph

Checking)

12+9=?21

21=21

12-9=?3

3=3

I hope this helped! If you have any questions, dm me on insta celinesaydawi

francocanacari

The speed of the boat in still water is 6 mph, and the speed of the current is 4.5 mph.

Given that a boat traveled 126 miles downstream and back, and the trip downstream took 6 hours, while the trip back took 42 hours, to determine what is the speed of the boat in still water and what is the speed of the current, the following calculations must be performed:

  • (126/2) / 6 = 10.5 mph downstream
  • (126/2) / 42 = 1.5 mph against current
  • (10.5 - 1.5) / 2 = 4.5 mph (current speed)
  • 10.5 - 4.5 = 6
  • 1.5 + 4.5 = 6
  • 6 mph = speed of the boat in still water

Therefore, the speed of the boat in still water is 6 mph, and the speed of the current is 4.5 mph.

Learn more in https://brainly.com/question/17579081

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