SOLUTION: The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total of 5 1/3 hr. Find the speed of his boat.
- I know that the dist
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-> SOLUTION: The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total of 5 1/3 hr. Find the speed of his boat.
- I know that the dist
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Question 112392: The speed of the current in a river is 2mph. Jay travels 20 miles upstream and then 20 miles downstream in a total of 5 1/3 hr. Find the speed of his boat.
- I know that the distance formula is supposed to be used to find this answer but i just cannot get it right. d=r.t Answer by checkley71(8403) (Show Source):
You can put this solution on YOUR website! 20/(S-2)+20/(S+2)=5 1/3
[20(S+2)+20(S-2)]/(S-2)(S+2)=16/3
(20S+40+20S-40)/(S^2-4)=16/3
40S/(S^2-4)=16/3 NOW CROSS MULTIPLY
16(S^2-4)=40S*3
16S^2-64=120S
16S^2-120S-64=0
8(2S^2-15S-8)=0
8(2S+1)(S-8)=0
S-8=O
S=8 ANSWER FOR THE SPEED OF THE BOAT.
20/(8-2)+20/(8+2)=16/3
20/6+20/10=16/3
(20*10+20*6)/60=16/3
(200+120)/60=16/3
320/60=16/3
16/3=16/3
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