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scott8148 answered: 6619 problems
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Polynomials-and-rational-expressions/270393: the water current is 2 miles per hour . a canoe can travel 6 mile downstream with the current, in the same amount of time it travel 2 miles upstream against the current. what is the canoe rate in still water?
1 solutions
Answer 198158 by scott8148(6628)   on 2010-02-16 19:19:46 (Show Source):
You can put this solution on YOUR website!t = d / r ___ times are the same, upstream and downstream
6 / (c + 2) = 2 / (c - 2)
"cross" multiplying ___ 6c - 12 = 2c + 4
4c = 16 ___ c = 4
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Volume/270006: Hi,
Can you please help me figure out how many gallons are in a container that is 64 inches in diameter and 12 feet long?
Thank you!
Michelle
1 solutions
Answer 197869 by scott8148(6628) on 2010-02-15 21:39:43 (Show Source):
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Miscellaneous_Word_Problems/269601: Two sides of a triangle have the same length. The third side measures 2m less than twice the common length. The perimeter of the triangle is 22m. What are the lengths of the three sides?
1 solutions
Answer 197575 by scott8148(6628) on 2010-02-14 19:39:12 (Show Source):
You can put this solution on YOUR website!"Two sides of a triangle have the same length" ___ 2x
"The third side measures 2m less than twice the common length" ___ 2x - 2
"The perimeter of the triangle is 22m" ___ 2x + 2x - 2 = 22
4x - 2 = 22 ___ x = 6
2x - 2 = 10
the sides are 6, 6 ,and 10
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Percentage-and-ratio-word-problems/269587: For lunch Robert had a sandwich and two glasses of milk for a total of 660 calories. The sandwich had 2.4 times as many calories as a glass of milk. How many calories were in the sandwich?
PLEASE PLEASE HELP
i want to do well!
1 solutions
Answer 197569 by scott8148(6628) on 2010-02-14 19:28:44 (Show Source):
You can put this solution on YOUR website!it is easier to solve for the milk first
let x=milk
" The sandwich had 2.4 times as many calories as a glass of milk" ___ 2.4x
"a sandwich and two glasses of milk for a total of 660 calories" ___ 2.4x + 2x = 660
4.4x = 660 ___ x = 150
sandwich = 2.4x = 360
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Probability-and-statistics/269541: Assume the balls in the box are numbered 1 through 8, and that an experiment consists of randomly selecting 3 balls one after another without replacement. What probability should be assigned to the event that at least one ball has an odd number?
1 solutions
Answer 197563 by scott8148(6628) on 2010-02-14 19:17:10 (Show Source):
You can put this solution on YOUR website!number of ways to select 3 out of 8 ___ 8C3 = 56
number of ways to select 3 even balls ___ 4C3 = 4
number of ways to select at least one odd ball ___ 56 - 4 = 52
probability of at least one odd ball ___ 52 / 56 = 13 / 14 = .93 (approx)
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test/269190: given log bA=2.435 and log bB=0.343
find log b A/B?
choose fro these four answers
1. 2.092
2. 0.835
3. 2.435
4. 2.778
1 solutions
Answer 197297 by scott8148(6628) on 2010-02-13 13:45:10 (Show Source):
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logarithm/269189: e^-t/4.6=1.73^2.7t The answer is t=0, how do you get this?
1 solutions
Answer 197295 by scott8148(6628) on 2010-02-13 13:42:33 (Show Source):
You can put this solution on YOUR website!if t=0, then the exponents are zero and (by definition) both sides equal one
this is a "default" solution ___ changing any or all other values in the equation does not change the solution
___ alternatively ___
taking the natural log ___ -t / 4.6 = ln(1.73) * 2.7t
multiplying by 4.6 ___ -t = ln(1.73) * 12.42t
adding t-ln(1.73) ___ -ln(1.73) = 13.42t
dividing by 13.42 ___ -ln(1.73) / 13.42 = t
t = -.0408 (approx)
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Miscellaneous_Word_Problems/269129: Point C is on the segment AB which has endpoints A(2, -1) and B(11, 5). Point C is twice as far from point A as it is from point B. What are the coordinates of point C?
1 solutions
Answer 197267 by scott8148(6628) on 2010-02-13 10:09:03 (Show Source):
You can put this solution on YOUR website!the AB distance is 9 on the x-axis and 6 on the y-axis
C is 2/3 of the distance from A to B
so the AC distance is 6 on the x-axis and 4 on the y-axis
C coordinates are (8, 3)
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Length-and-distance/269120: As part of flight training a student pilot was required to fly to an airport and then return. The average speed on the way to the airport was 115 mph, and the average speed returing was 172.5 mph. Find the distance between the two airports if the total flying time was 5 hours.
1 solutions
Answer 197265 by scott8148(6628) on 2010-02-13 10:02:30 (Show Source):
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Travel_Word_Problems/269014: In two hours a boat is rowed downstream 4 miles and back again. If the speed of the stream is 1.5 kts what is that of the boat?
1 solutions
Answer 197263 by scott8148(6628) on 2010-02-13 09:50:46 (Show Source):
You can put this solution on YOUR website![4 / (b + 1.5)] + [4 / (b - 1.5)] = 2
4b - 6 + 4b + 6 = 2 (b^2 - 2.25)
0 = b^2 - 4b - 2.25
use quadratic formula to find b
miles and kts are NOT in the same units
___ this solution does not contain a correction for the difference
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Probability-and-statistics/269008: the depth of fluid,H cm, in a vessel at time t minutes is given by
H = 16+4t+2t^2-(t^3/16)
determine the rate at which the depth is changing after 4 minutes.
if the cross section of the vessel is circular,of diameter 2 m, determine the rate of filling in m3 min-1,at this time.
1 solutions
Answer 197258 by scott8148(6628) on 2010-02-13 09:38:44 (Show Source):
You can put this solution on YOUR website!this is a differential calculus problem using the first derivative of depth with respect to time
dH/dt = 4 + 4t - (3/16)t^2
substituting 4 for t gives a rate of 17 cm/min
the volume rate is ___ .17 pi m^3/min
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Travel_Word_Problems/269070: Write the equation of each line. Give the answer in standard
form using only integers as the coefficients.
The line through (3, 4) that is parallel to the line 5x + 3y = 9.
1 solutions
Answer 197209 by scott8148(6628) on 2010-02-12 22:07:19 (Show Source):
You can put this solution on YOUR website!parallel means same slope ___ so the x and y coefficients are the same
the constant term changes ___ just substitute the given coordinates to find the new term
5(3) + 3(4) = 27
5x + 3y = 27
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Travel_Word_Problems/268577: Jim can fill a pool carrying buckets of water in 30 minutes. Sue can do the same job in 45 minutes. Tony can do the same job in 1 ½ hours. How quickly can all three fill the pool together? (answer in minutes) Please show steps
1 solutions
Answer 196815 by scott8148(6628) on 2010-02-11 16:18:04 (Show Source):
You can put this solution on YOUR website!they each fill a FRACTION of the pool, based on their individual rates
___ the fractions sum to one -- the WHOLE pool
(x / 30) + (x / 45) + (x / 90) = 1
multiplying by 90 (LCD) ___ 3x + 2x + x = 90
6x = 90 ___ x = 15
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Travel_Word_Problems/268553: The President of a company traveled 1600 miles by jet and 400 miles on a prop plane. The rate of the jet is four times the rate of the prop plane. The entire trip took 10 hours. Find the rate of the jet plane. ___mph
I tried 1600/4x+ 400/x = 10 hours and my answers was 160 mph which apparently is wrong How would I set this up to get the correct answer. I am an online student and this answer is due by 10 p.m. 2-11-2010
1 solutions
Answer 196810 by scott8148(6628) on 2010-02-11 16:11:24 (Show Source):
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Equations/268286: Please help with this problem, this is what I have so far:
Problem: Height of a projected ball,
An astronaut on the moon throws a baseball upward. The astronaut is 6ft., 6in. tall, and the initial velocity of the ball is 30 ft. per sec. The height S of the ball in feet is given by the equation
S= -2.7t^2 + 30t + 6.5
where t is the number of seconds after the ball was thrown.
A.) After how many seconds is the ball 12ft above the moon's surface? Round to the nearest hundreth.
I know I have to look for the seconds, which is t so then I have to solve for S, the height. This is have I've got so far:
12 = 2.7t^2 + 30t + 6.5
-12 -12
------------------------
0 = 2.7t^2 + 30t - 5.5
B.)How many seconds will it take fore the ball to return to the surface? Round to the nearest hundredth.
So on the second part of the equation I have to look for the time, so that means that I have to solve for the height...
Thanks for your help in advance.
1 solutions
Answer 196655 by scott8148(6628) on 2010-02-10 20:21:53 (Show Source):
You can put this solution on YOUR website!A.) just use the quadratic formula on the equation you generated and solve for t
___ watch the signs (your equation has an incorrect sign for the coefficient of the squared term)
B.) substitute zero for S in the original equation (S= -2.7t^2 + 30t + 6.5) and use the quadratic formula
check the solutions for t to see if they make sense
___ A should have two solutions (upward and downward)
___ B should have one solution (negative value not realistic)
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Linear-systems/268267: 4 Cheeseburgers and two shakes cost a total of 7.90. Two shakes cost 15 cents more than one cheeseburger. How much is a cheeseburger and the shake?
1 solutions
Answer 196646 by scott8148(6628) on 2010-02-10 20:02:30 (Show Source):
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Linear_Equations_And_Systems_Word_Problems/267359: Can you please provide the algebraic expression for this word problem.
Play tickets for two adults and two children cost $24. A child's ticket costs half as much as an adult's ticket. Find the cost of a child's ticket.
1 solutions
Answer 196263 by scott8148(6628) on 2010-02-08 22:44:29 (Show Source):
You can put this solution on YOUR website!"Play tickets for two adults and two children cost $24" ___ 2a + 2c = 24 ___ 2a = 24 - 2c ___ a = 12 - c
"A child's ticket costs half as much as an adult's ticket" ___ c = a / 2 ___ 2c = a
substituting ___ 2c = 12 - c ___ 3c = 12 ___ c = 4
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Proportions/267069: A person who is 6 feet tall walks away from a 50-foot silo toward the tip of the silo's shadow. At a distance of 32 feet feet from the silo, the person's shadow begins to emerge beyond the silo's shadow. How much farther must the person walk to be completely out of the silo's shadow?
1 solutions
Answer 196139 by scott8148(6628) on 2010-02-08 14:38:32 (Show Source):
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Money_Word_Problems/267061: A girl has a collection of 425 coins consisting of pennies, nickels and dimes. she has 50 more nickels than pennies and 25 more dimes than nickels. how many coins of each kind does she have?
1 solutions
Answer 196137 by scott8148(6628) on 2010-02-08 14:30:07 (Show Source):
You can put this solution on YOUR website!p + n + d = 425
n = p + 50
d = n + 25 ___ d = (p + 50) + 25 ___ d = p + 75
p + (p + 50) + (p + 75) = 425
3p + 125 = 425
p = 100
n = 150
d = 175
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Average/267059: A student has scores of 83, 89, 78, and 86 on her first four tests. what score must she get on her fifth exam so that the average for all 5 exams is 85 or higher?
1 solutions
Answer 196132 by scott8148(6628) on 2010-02-08 14:22:13 (Show Source):
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Travel_Word_Problems/267091: If you drove to Austin at 70 miles per hour and returned at 50 miles per hour. What is the distance driven to Austin if total driving time was 7.2 hours?
I've tried;
D (distance)=R (rate/MPH)*T (time)
D=R*T
D=70+50*7.2
D=864
1 solutions
Answer 196122 by scott8148(6628) on 2010-02-08 14:03:51 (Show Source):
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