Here's a fun elementary algebra problem...
A boat travels 26 miles up a river in the same amount of time it takes to travel 34 miles down the same river. If the current is 2 mph, what is the speed of the boat in still water?
Hint: t= d/r
2006-08-04 10:02:41 · 13 answers · asked by humble.earthling 2 in Science & Mathematics ➔ Mathematics
The boat is moving. What is meant by "still" is that there is no current.
2006-08-04 10:09:08 · update #1
The type of boat doesn't matter in the mathematical equation, but from the speeds given, you would expect it to be a motor boat.
2006-08-04 10:11:16 · update #2
LUCKY DUCKY - Your answer is wrong. And annoying.
2006-08-04 10:15:32 · update #3
15 mph
2006-08-04 10:11:11 · answer #1 · answered by Earl Morton 2 · 1⤊ 0⤋
Given
26 = distance up the river
34 = distance down triver
x + 2 = resitance of the cuttent up the river
x - 2 = no resistance of the cureent down the river
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Forming the formula
26(x + 2) = The distance plus the resistance of the current traveled up the river.
34((x - 2) The distance minus the resistance of the cureent traveled down the river
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The formula
26(x + 2) = 34(x - 2)
26x + 52 = 34x - 68
The distribute property
26x + 52 = 34 - 68
+ 68 +68
Adding + 69 to both sibes of the equation
26x + 120 = 34x
-26x -26x
Subtracting - 25x from both sides of the equation
120 = 8 x
120/8 = 8x/8
Dividing 8 by both sides of the equation
15 = x
The answwer is x = 15
The speed ot the boat Traveling up river is 17 miles per hour.
The speet of the boat traveling down River is 13 miles per hour
2006-08-05 12:45:35 · answer #2 · answered by SAMUEL D 7 · 0⤊ 0⤋
0 mph. In still water, there will be no current, therefore, the boat cannot be moving, unless it is a sailboat with the sails up, and you didn't include that information into the question.
If by "still", you mean that there is a 2-mph undertow or current, then the boat will be moving at a rate of around .5 to 1 mph.
By the way... Nautically, the term is "knots", NOT mph. Miles Per Hour is a land term, and shouldn't be used in any body of water. A knot is 6076 feet per hour, and a mile is 5280 miles per hour.
--
Lucky Ducky
2006-08-04 10:14:02 · answer #3 · answered by Lucky Ducky 2 · 0⤊ 0⤋
Assuming the motor on the boat runs the same both ways.
26 = t (x -2)
34 = t (x+2)
where t is the time and x is how fast the motor is running. put the equation in terms of t.
26/(x-2) = t
34/(x+2) = t
26/(x-2) = 34/(x+2)
26(x+2) = 34(x - 2)
26x + 52 = 34x - 68
120 = 8x
15 = x
The boat is traveling 15 miles per hour.
Knots... miles per hour... who cares... its a math problem.. they don't have to make sense.
2006-08-04 10:14:58 · answer #4 · answered by John H 3 · 0⤊ 0⤋
Let speed be x
up the stream speed = x-2
down the stream x+2
26/(x-2) = 34/(x+2)
or 26(x+2) = 34(x-2)
or 26x+52 = 34x -68
transposing 15x = 120 or x = 15 is the speed
2006-08-04 11:47:35 · answer #5 · answered by Mein Hoon Na 7 · 0⤊ 0⤋
If the boat is in still water. Doesnt it mean it isnt moving? so the speed would be 0.
2006-08-04 10:08:00 · answer #6 · answered by Anonymous · 0⤊ 0⤋
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2016-10-15 11:06:35 · answer #7 · answered by ? 4 · 0⤊ 0⤋
t1=t2 same amount of time
t=d/r
so d1/r1=d2/r2
x is velocity of boat in still water
26/(x-2)=34/(x+2)
13(x+2)=17(x-2)
4x=60
x=15.
The boat would be travelling 15mph in still water.
And... the time is 2 hours.
2006-08-04 10:17:42 · answer #8 · answered by TRE 3 · 0⤊ 0⤋
Who cares if it is a party boat with some Vikings players on it.
2006-08-04 10:15:48 · answer #9 · answered by shonben2000 1 · 0⤊ 0⤋
is it a motor boat or a sail boat?
2006-08-04 10:09:22 · answer #10 · answered by legendaryfrog 3 · 0⤊ 0⤋