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15390..15419 , 15420..15449 , 15450..15479 , 15480..15509 , 15510..15539 , 15540..15569 , 15570..15599 , 15600..15629 , 15630..15659, >>NextPercentage-and-ratio-word-problems/738184: I need help with a question.It is:The ratio of boys to girls in Mr.Cashtro's Religion class is 5:4 .What percent of students are boys?
I tried to divide 5/4 to get 1.25 then i put the whole class in a percent and got 125 and divide that by four to get 31.25 but i know thats not the answer....I am just confused and we have a test tommorow.anwser Asap 1 solutions
Answer 450737 by ankor@dixie-net.com(15652) on 2013-04-16 08:35:36 (Show Source):
You can put this solution on YOUR website!The ratio of boys to girls in Mr.Cashtro's Religion class is 5:4 .
What percent of students are boys?
:
Percent is the boy or girl relationship to whole class which we can represent with 5+4=9.
Boys are represented by 5, therefore
 * 100 = 55.56% are boys
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Age_Word_Problems/737981: The average age of rolfe and jam gives the age of kyle. 3 years ago, the sum of ages of rolfe, jam and kyle was 66. 5 years from now. kyle will be as old as jam now. What are their present ages?
Please solve this problem for my daughter.. thank you so much :D 1 solutions
Answer 450679 by ankor@dixie-net.com(15652) on 2013-04-15 21:54:01 (Show Source):
You can put this solution on YOUR website!Write an equation for each statement:
:
"The average age of rolfe and jam gives the age of kyle."
k = 
mult both sides by 2
2k = r + j
:
" 3 years ago, the sum of ages of rolfe, jam and kyle was 66."
(r-3) + (j-3) + (k-3) = 66
r + j + k - 9 = 66
r + j + k = 66+9
r + j + k = 75
From the 1st statement, replace r + j with 2k
2k + k = 75
3k = 75
k = 75/3
k = 25 yrs is Kyle's age
:
" 5 years from now. kyle will be as old as jam now."
k + 5 = j
replace k with 25
25 + 5 = j
j = 30 yrs is Jam's age
:
Find r's age using the 1st statement
2k = r + j
2(25) = r + 30
50 - 30 = r
r = 20 yrs is Rolf's age
:
What are their present ages? we answered that.
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Average/738042: The average of five numbers a 34,one more number is added then the average become 35. What was the number added? 1 solutions
Answer 450676 by ankor@dixie-net.com(15652) on 2013-04-15 21:41:29 (Show Source):
You can put this solution on YOUR website!The average of five numbers a 34,
one more number is added then the average become 35.
What was the number added?
:
 = 35
170 + n = 6(35)
n = 210 - 170
n = 40 is the number added
:
:
You can confirm this for yourself
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Miscellaneous_Word_Problems/737640: A farmer wishes to make three equal sized rectangular corrals. The outside fence costs $3/ft and the inside fence costs $1/ft. If she has $1200 to spend on the corrals, what dimensions will provide the corrals of greatest area? {All three are drawn right next to each other-picture three hersheys chocolate bars lined up long side by long side; the outside perimeter would be X (for the long edge) and Y (for the 3 short ends) Hope that helps and does not confuse.} 1 solutions
Answer 450564 by ankor@dixie-net.com(15652) on 2013-04-15 10:24:57 (Show Source):
You can put this solution on YOUR website!A farmer wishes to make three equal sized rectangular corrals.
The outside fence costs $3/ft and the inside fence costs $1/ft.
If he has $1200 to spend on the corrals, what dimensions will provide the corrals of greatest area?
:
The fence consists of 3 widths and 2 lengths, one width will cost $1 a foot
the other two cost $3, as does the 2 lengths
:
3(2L) + 3(2W) + 1(W) = 1200
6L + 6W + W = 1200
6L + 7W = 1200
6L = 1200-7W
L = 
:
Area = L * W
replace L
A =  * W
A = 
divide both coefficients by 6, write it as a quadratic equation
A =  W^2 + 200W
Max area occurs on the axis of symmetry, find that with x =-b/(2a)
w = 
using decimals here
w = 
w ~ 85.7 ft is the width
Find the length
L = 
do the math
L ~ 100 ft is length for max area for $1200
:
:
You should check this out for math errors
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Miscellaneous_Word_Problems/737541: A Large pizza 16in diameter for $15.00 or Medium pizza 8in diameter for $7.50. Compare unit rate: Cost per square inch. 1 solutions
Answer 450484 by ankor@dixie-net.com(15652) on 2013-04-14 21:38:44 (Show Source):
You can put this solution on YOUR website!A Large pizza 16in diameter for $15.00 or Medium pizza 8in diameter for $7.50. Compare unit rate: Cost per square inch.
:
Change $ to cents
:
large has a radius of 8"
 ~ 7.5 cents per sq/in
:
Med has a radius of 4"
 ~ 14.92 cents per sq/in
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Miscellaneous_Word_Problems/737399: A lifeguard is interested in enclosing a rectangular swimming area along the beach. The swimming area will be enclosed using 72m of floating rope and will be bordered on one side by the beach: that is the problem
these are the questions
a. Draw a sketch to model the situation
b. Find the dimensions (length and width) that provide the maximum area for swimming.
c. What is the maximum area available for swimming?
Please could someone help me with this today 1 solutions
Answer 450475 by ankor@dixie-net.com(15652) on 2013-04-14 21:23:51 (Show Source):
You can put this solution on YOUR website!A lifeguard is interested in enclosing a rectangular swimming area along the beach.
The swimming area will be enclosed using 72m of floating rope and will be bordered on one side by the beach: that is the problem these are the questions
:
a. Draw a sketch to model the situation
I'll let you handle this
:
b. Find the dimensions (length and width) that provide the maximum area for swimming.
Only 3 sides are required therefore
L + 2W = 72
L = (72-2W)
:
c. What is the maximum area available for swimming?
A = L * W
Replace L with (72-2W)
A = W(72-2W)
A quadratic equation
A = -2W^2 + 72W
Max area occurs on the axis of symmetry, find it using formula: x = -b/(2a)
W = 
W = 18 m is the width that gives max area
then
L = 72 - 2(18) = 36 m is the length for max area
:
Actual max area: 18 * 36 = 648 sq/m
:
:
If you graph the equation you can see that max area occurs when x=18 (width)
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Surface-area/737621: the surface area of a cylinder is 1000 pi square centimeters. the radius of the cylinder is four times the height. what is the height of the cylinder. only reply if u see this within 2 hours. its very time sensitive 1 solutions
Answer 450468 by ankor@dixie-net.com(15652) on 2013-04-14 20:51:51 (Show Source):
You can put this solution on YOUR website! the surface area of a cylinder is 1000 pi square centimeters.
the radius of the cylinder is four times the height.
what is the height of the cylinder.
:
LET x = the height
"radius is 4 time the height" therefore
4x = the radius
:
S.A. =  + 
so we have
 +  = 
divide equation by 2pi
 = 500
 = 500
 = 500
divide both sides by 20
 = 25
x = 
x = 5 is the height
:
You can check the math on this,
|
Travel_Word_Problems/737484: A car passes a landmark on a highway traveling at a constant rate of 55 kilometers per hour. An hour later, a second car passes the same landmark traveling in the same direction at 75 kilometers per hour. How much time after the second car passes the landmark will it overtake the first car? 1 solutions
Answer 450429 by ankor@dixie-net.com(15652) on 2013-04-14 16:47:17 (Show Source):
You can put this solution on YOUR website!A car passes a landmark on a highway traveling at a constant rate of 55 kilometers per hour.
An hour later, a second car passes the same landmark traveling in the same direction at 75 kilometers per hour.
How much time after the second car passes the landmark will it overtake the first car?
:
Let t = time for the 2nd car to catch the 1st
From the information given, we know that the first car is 55 km ahead of the 2nd
car when it passes the marker.
:
write a distance equation, dist = speed * time
75t = 55t + 55
75t - 55t = 55
20t = 55
t = 55/20
t = 2.75 hrs or 2 hrs 45 min
|
Linear-systems/737411: A lemming runs from a point A to a cliff at 4m/s,jumps over the edge at B and falls at C at an average speed of 25 m/s,if the total distance from A to C is 500 metres and the time taken for the journey is 41 seconds,find the height Bc of the cliff. 1 solutions
Answer 450378 by ankor@dixie-net.com(15652) on 2013-04-14 12:28:45 (Show Source):
You can put this solution on YOUR website!A lemming runs from a point A to a cliff at 4m/s,jumps over the edge at B and falls at C at an average speed of 25 m/s,
if the total distance from A to C is 500 metres and the time taken for the journey is 41 seconds, find the height Bc of the cliff.
:
let c = height of the cliff
total A to C distance given as 500m
(500-c) = distance from A to B
:
Write a time equation; time = dist/speed
:
Run time + fall time = 41 sec
 +  = 41
multiply by 100, clears the denominators,
25(500-c) + 4c = 4100
12500 - 25c + 4c = 4100
-25c + 4c = 4100 - 12500
-21c = -8400
c = -8400/-21
c = 400 meter clif
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Age_Word_Problems/737365: The difference between the ages of two men is 10 years.15 years ago the older was twice the younger .What are their present ages? 1 solutions
Answer 450370 by ankor@dixie-net.com(15652) on 2013-04-14 11:10:44 (Show Source):
You can put this solution on YOUR website!let a = the age of the older man
:
"The difference between the ages of two men is 10 years."
a - 10 = age of the younger
:
"15 years ago the older was twice the younger ."
a - 15 = 2(a-10-15)
a - 15 = 2(a-25)
a = 2a - 50 + 15
a = 2a - 35
35 = 2a - a
a = 35 now
:
What are their present ages?
|
Average/737357: I don't really understand how to solve this type of problems
Q:In a boat 25 persons were sitting. Their average weight increased one kilogram when one man goes and a new man comes in. The weight of the new man is 70 kgs. Find the weight of the man who is going. 1 solutions
Answer 450366 by ankor@dixie-net.com(15652) on 2013-04-14 11:03:24 (Show Source):
You can put this solution on YOUR website!:In a boat 25 persons were sitting.
Their average weight increased one kilogram when one man goes and a new man comes in.
The weight of the new man is 70 kgs. Find the weight of the man who is going.
:
let x = average weight of the 25 people and the weight of the guy that left
:
1 guy is replaced by 70 kg guy
 = x + 1
24x + 70 = 25(x+1)
24x + 70 = 25x + 25
70 - 25 = 25x - 24x
45 = x
:
The guy that left weighed 45 kg
|
Miscellaneous_Word_Problems/736931: A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second.
Write an equation that gives the height (in feet) of the football as a function of the time (in seconds) since it was punted.
Find the height (in feet) of the football 2 seconds after the punt.
Calculate how many seconds after the punt the ball would hit the ground. 1 solutions
Answer 450296 by ankor@dixie-net.com(15652) on 2013-04-13 21:51:35 (Show Source):
You can put this solution on YOUR website!A kicker punts a football from 3 feet above the ground with an initial velocity of 47 feet per second.
Write an equation that gives the height (in feet) of the football as a function of the time (in seconds) since it was punted.
h = -16t^2 + 47t + 3
:
Find the height (in feet) of the football 2 seconds after the punt.
t=2
h = -16(2^2) + 47(2) + 3
h = -64 + 94 + 3
h = 33 ft after 2 seconds
:
Calculate how many seconds after the punt the ball would hit the ground.
h = 0
-16t^2 + 47t + 3 = 0
mult by -1, easier to factor
16t^2 - 47t - 3 = 0
Factors to
(16t+1)(t-3) = 0
the positive solution
t = 3 seconds to hit the ground
:
Graphically, (green line at 33 ft)
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Travel_Word_Problems/737280: A truck left city a and b respectively, at the same time traveling toward each other. When they met, the track had traveled 120 more miles than the van. Afterwards, the van traveled 9 more hours to reach city B while the truck traveled 4 more hours to reach city A. What is the distance between the 2 cities?
PLEASE HELP!!!!! 1 solutions
Answer 450295 by ankor@dixie-net.com(15652) on 2013-04-13 21:26:08 (Show Source):
You can put this solution on YOUR website!A van and a truck left city a and b respectively at the same time traveling toward each other.
When they met, the truck had traveled 120 more miles than the van.
Afterwards, the van traveled 9 more hours to reach city B while the truck traveled 4 more hours to reach city A.
What is the distance between the 2 cities?
:
let x = distance from a to meeting point (initially traveled by the van)
then
(x+120) = distance from b to meeting point (initially traveled by the truck)
therefore
(2x+120) = distance from a to b
:
Speed = dist/time
 = speed of the van traveling to b
 = speed of the truck traveling to a
:
Let t = travel time for both to the meeting point (time = dist/speed)
Truck time
 = (x+120)*  = 
Van time
 = x *  = 
Times are equal, therefore
 = 
cross multiply
9x^2 = (4x+480)(x+120)
FOIL
9x^2 = 4x^2 + 480x + 480x + 57600
0 = 4x^2 - 9x^2 + 960x + 57600
-5x^2 + 960x + 57600 = 0
simplify, divide by-5
x^2 - 192x - 11520 = 0
Factors to
(x-240)(x+48) = 0
The positive solution
x = 240
a to b distance; 2(240) + 120 = 600 miles
:
:
We can confirm this, find the speed of each
240/4 = 60 km/hr the truck
360/9 = 40 km/hr the van
:
Time to meet point should be the same
truck: 360/60 = 6 hrs
van: 240/40 = 6 hrs
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Quadratic_Equations/737245: Buried treasure. Ahmed has half of a treasure map,which indicates that the treasure is buried in the desert 2x + 6 paces from Castle Rock. Vanessa has the other half of the map. Her half indicates that to find the treasure, one must get to Castle Rock, walk x paces to the north, and then walk 2x + 4 paces to the east. If they share their information, then they can find x and save a lot of digging. What is x? help me set it up please . 1 solutions
Answer 450264 by ankor@dixie-net.com(15652) on 2013-04-13 18:27:19 (Show Source):
You can put this solution on YOUR website!Ahmed has half of a treasure map,which indicates that the treasure is buried in the desert 2x + 6 paces from Castle Rock.
Vanessa has the other half of the map.
Her half indicates that to find the treasure, one must get to Castle Rock, walk x paces to the north, and then walk 2x + 4 paces to the east.
:
draw this out and you can see a right triangle with:
x = one leg
(2x+4) = another leg
(2x+6) = the hypotenuse
therefore using Pythagoras:
x^2 + (2x+4)^2 = (2x+6)^2
FOIL
x^2 + 4x^2 + 8x + 8x + 16 = 4x^2 + 12x + 12x + 36
5x^2 + 16x + 16 = 4x^2 + 24x + 36
combine like terms in the left
5x^2 - 4x^2 + 16x - 24x + 16 - 24x = 0
a quadratic equation
x^2 - 8x - 20 = 0
Factor to:
(x-10)(x+2) = 0
the positive solution
x = 10
:
Walk 10 paces north, 24 paces east, that point will be 26 paces from C.R.
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Equations/736937: The sum of the reciprocal of a number and the reciprocal of 3 less than the number is 6 times the reciprocal of the original number. Find the original number 1 solutions
Answer 450258 by ankor@dixie-net.com(15652) on 2013-04-13 17:15:06 (Show Source):
You can put this solution on YOUR website! The sum of the reciprocal of a number and the reciprocal of 3 less than the number is 6 times the reciprocal of the original number.
Find the original number
:
let n = original number
:
 +  = 
multiply by n(n-3), resulting in
(n-3) + n = 6(n-3)
n - 3 + n = 6n - 18
2n - 6n = -18 + 3
-4n = -15
n = -15/-4
n = +3.75 is the original number
:
:
Expected an integer here, see if this checks out:
 +  = 
.267 + 1.333 = 1.6, it does!
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Circles/737060: In the circle, central angle AOB measures 45 degrees the arc is AB 3.14 cm long. How many cm is the radius? 1 solutions
Answer 450222 by ankor@dixie-net.com(15652) on 2013-04-13 13:36:46 (Show Source):
You can put this solution on YOUR website!In the circle, central angle AOB measures 45 degrees the arc is AB 3.14 cm long. How many cm is the radius?
:
Find the circumference
 * 3.14 = 25.12 cm
Find the radius
 = 25.12
r = 
r = 3.998 ~ 4 cm is the radius
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Travel_Word_Problems/737030: a passenger plane made a trip between two cities in 3 hours. a cargo plane made the same trip in 4 hours. if the passenger plane flew at 75 miles per hour faster, how fast did the cargo plane fly?
1 solutions
Answer 450211 by ankor@dixie-net.com(15652) on 2013-04-13 12:47:28 (Show Source):
You can put this solution on YOUR website!a passenger plane made a trip between two cities in 3 hours.
a cargo plane made the same trip in 4 hours. if the passenger plane flew at 75 miles per hour faster, how fast did the cargo plane fly?
:
Let s = speed of the cargo plane
then
(s+75) = speed of the pass plane
:
let d = distance between the two cities
;
Write an time equation for each plane's trip
d/s = 4
therefore:
d = 4s
and
d/(s+75) = 3
:
replace d with 4s
 = 3
4s = 3(s+75)
4s = 3s + 225
4s - 3s = 225
s = 225 mph is the speed of the cargo plane
:
:
You can confirm this, find d and check the times with 225 and 300 mph
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Quadratic_Equations/737018: A student did a word-processing job for $40. It took him 5 hours longer than he expected, and therefore he earned $4 per hour less than he anticipated. How long did he expect that it would take to do the job? 1 solutions
Answer 450195 by ankor@dixie-net.com(15652) on 2013-04-13 11:32:02 (Show Source):
You can put this solution on YOUR website!A student did a word-processing job for $40.
It took him 5 hours longer than he expected, and therefore he earned $4 per hour less than he anticipated.
How long did he expect that it would take to do the job?
:
let x = expected hourly wage
then
(x-4) = actual hourly wage
:
predicted time = actual time - 5 hrs
 =  - 5
multiply by x(x-4), results:
40(x-4) = 40x - 5x(x-4)
40x - 160 = 40x + -5x^2+20x
subtract 40x from both sides, arrange as a quadratic eq on the left
5x^2 - 20x - 160 = 0
simplify, divide by 5
x^2 - 4x - 32 = 0
Factors to:
(x-8)(x+4) = 0
the positive solution
x = $8 an hr expected
:
:
Find the expected hrs required:
40/8 = 5 hrs
Find the actual hrs:
40/4 = 10 hrs
------------------
difference: 5 hrs
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logarithm/736911: ln[x^10sqrt(x^2+2)/(x+5)^15]
I need to expand the logarithm as much as possible without a calculator. The square root is over the entire (x^2+2). I've already tried submitting ln(x^11+1)-15ln(x+5) 1 solutions
Answer 450150 by ankor@dixie-net.com(15652) on 2013-04-12 21:28:46 (Show Source):
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Volume/736970: A circular cylinder is 60 inches in height and has a volume of 30 gallons. water is flowing into the cylinder at the rate of 5 gallons per minute. At what rate is the level of water in the cylinder increasing?
I need this solved asap. Thank you in advance for your help. 1 solutions
Answer 450146 by ankor@dixie-net.com(15652) on 2013-04-12 20:20:09 (Show Source):
You can put this solution on YOUR website! A circular cylinder is 60 inches in height and has a volume of 30 gallons.
water is flowing into the cylinder at the rate of 5 gallons per minute.
At what rate is the level of water in the cylinder increasing?
:
30 gallons = 231*30 = 6930 cu/inches
:
Find the radius of the cylinder
pi*r^2*60 = 6930
 =
 = 36.7648
r = 
r ~ 6.1 inches
:
Find the height (h) of a cylinder of 5 gallons of water
5 * 231 = 1155 cu/inches
:
 = 1155
h = 
h = 9.99 ~ 10 inches per minutes
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Travel_Word_Problems/736991: Two escaped convicts are headed east on the railroad tracks. They come to a mile-long tunnel; they have little choice but to enter. They are 0.4 mile into the tunnel when they hear an eastbound train closing in on them from behind. Oh no!
Snap decisions are required. The younger, faster convict decides to run the 0.4 mile back out of the tunnel (even though the train is coming at him!). The older and slower convict decides to run the remaining 0.6 mile to the far end of the tunnel. (He will run away from the train because it gives him more time to escape.)
The fast convict runs at 11 miles per hour; the slower convict runs at 7 miles per hour. The train travels at a steady rate. Each man manages to exit the tunnel at the last possible second. Close calls!
Question: what was the speed of the train? 1 solutions
Answer 450119 by ankor@dixie-net.com(15652) on 2013-04-12 16:48:31 (Show Source):
You can put this solution on YOUR website!Two escaped convicts are headed east on the railroad tracks.
They come to a mile-long tunnel; they have little choice but to enter.
They are 0.4 mile into the tunnel when they hear an eastbound train closing in on them from behind. Oh no!
Snap decisions are required.
The younger, faster convict decides to run the 0.4 mile back out of the tunnel (even though the train is coming at him!).
The older and slower convict decides to run the remaining 0.6 mile to the far end of the tunnel.
(He will run away from the train because it gives him more time to escape.)
The fast convict runs at 11 miles per hour; the slower convict runs at 7 miles per hour.
The train travels at a steady rate.
Each man manages to exit the tunnel at the last possible second. Close calls!
Question: what was the speed of the train?
:
Find the time required by the faster guy to get to the near end of the tunnel
.4/11
At this time the train enters the tunnel
The slower guy has traveled 7 * .4/11 = .25454 mi so he is:
.6 - .25454 = .3454 mi to the end of the tunnel
He has to travel .3454 mi while the train travels 1 mile
let t = speed of the train
 = 
Cross multiply
.3454t = 7*1
t = 
t = 20.3 mph is the speed of the train
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Travel_Word_Problems/736876: John drives along a straight motorway at a constant speed for 120km. Next day he completes the same journey travelling 10km/h faster. He completes this journey in 10 mins less than the first journey. find the 2 speeds at which he travelled.
Please help!I know d=s x t.
120=t x s
120= t-10 x s + 10.
Have come up with various answers- none of them right! 1 solutions
Answer 450055 by ankor@dixie-net.com(15652) on 2013-04-12 10:06:42 (Show Source):
You can put this solution on YOUR website! John drives along a straight motorway at a constant speed for 120km.
Next day he completes the same journey travelling 10km/h faster.
He completes this journey in 10 mins less than the first journey.
find the 2 speeds at which he travelled.
:
let s = his first speed
then
(s+10) = his faster speed
:
change 10 min to 1/6 hr
:
Write a time equation, time = dist/speed:
:
 -  = 
multiply by 6s(s+10) to clear the denominators, resulting in:
6(s+10)*120 - 6s(120) = s(s+10)
120(6s+60) - 720s = s^2 + 10s
720s + 7200 - 720s = s^2 + 10s
a quadratic equation
0 = s^2 + 10s - 7200 = 0
Factors to
(s+90)(s-80) = 0
the positive solution all we want here
s = 80 km/hr and 90 km/hr are the two speeds
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Travel_Word_Problems/736505: a Kayaker traveled 20km/h into the current and 7/5 the speed with the current, What is the speed of the kayaker in still water and what is the speed of the current?
A motorcycle breaks down and the rider must walk the rest of the way to work. the motorcycle averaged 55mph, and the rider walks at the speed of 5mph. The distance from home to work is 100 miles, and the totale time for the trip was 4 hours. how far did the motorcycle rider walk? 1 solutions
Answer 449955 by ankor@dixie-net.com(15652) on 2013-04-11 18:23:43 (Show Source):
You can put this solution on YOUR website! a Kayaker traveled 20km/h into the current and 7/5 the speed with the current,
What is the speed of the kayaker in still water and
what is the speed of the current?
:
Find 7/5 of the speed of 20 km/h
 *20 = 28 km/hr
:
let s = speed in still water
let c = the rate of the current
then write an equation for each way
s + c = 28
s - c = 20
------------Addition eliminates c, find s
2s = 48
s = 48/2
s = 24 km/h in still water
:
I'll let you find the current.
:
:
A motorcycle breaks down and the rider must walk the rest of the way to work.
the motorcycle averaged 55mph, and the rider walks at the speed of 5mph.
The distance from home to work is 100 miles, and the total time for the trip was 4 hours.
how far did the motorcycle rider walk?
:
let w = distance walked
the total distance is 100 mi, therefore:
(100-w) = distance rode
:
Write a time equation time = dist/speed
ride time + walk time = 4 hrs
 +  = 4
Multiply by 55 to clear the denominators, resulting in:
100 - w + 11w = 55(4) 10w = 220 - 100
10w = 120
w = 120/10
w = 12 miles he walked!
:
:
You can check this by finding the actual times he walked and rode
12/5 =
88/55 =
---------
total time ___
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