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35 items are filed under this topic.
An egg falls from rest 2018-05-10
From Amy:
An egg falls from rest a distance of 75cm to the floor. Neglecting air resistance, at what speed does it hit the floor?
Answered by Penny Nom.
Tiling a floor 2016-03-05
From joanne:
How many floor tiles 20x20 inch do I need for area of 8x 12 ft.?
Answered by Penny Nom.
Tiling a room 2015-02-16
From Owen:
nicolas room is 56m2 she wants to put tiles down which are 50cm by 50cm each cost 4 how much money will she spend
Answered by Penny Nom.
Cumulative Frequency Math Question 2013-03-20
From Primadonna:


Please help me solve this question.

Thank you so much.

The cumulative frequency table below shows the length of time that 30 students spent text messaging on a weekend.

Minutes Used Cumulative Frequency
31-40 2
31-50 5
31-60 10
31-70 19
31-80 30

Which 10-minute interval contains the first quartile?

(1) 31–40

(2) 41–50

(3) 51–60

(4) 61–70

Answered by Penny Nom.
Tiling a floor 2013-03-18
From whitley:
Question from Whitley, a student:

How many square feet of tile do you need to cover the floor of a room that is 20ft, 25ft, 15ft, 20ft, 5ft, and 5ft

I made a replica of the floor

Answered by Penny Nom.
An electron in a TV tube 2013-02-15
From anu:
an electron in a TV tube is beamed horizontally at a speed of (50^6) m/sec. towards the face of a tube 40 cm away about how far will the electron drop before it hits? no information has been provided of initial height from where it is beamed.
Answered by Robert Dawson.
Percentiles 2012-10-17
From Kenneth:
Question from Kenneth:


What is a common calculation used to determine percentiles?

For example, five employees have the following salaries:

Office worker 1 - $25,000

Office worker 2 - $27,000

Office worker 3 - $30,000

Office worker 4 - $32,000

Office worker 5 - $35,000

What is the percentile rank of office worker 3 who earns $30,000?

Here's what I know: Add the number of salaries. Total: 5

Add the smallest number of salaries less than $30,000. There are two.

Now, divide 2 by 5 and multiply by 100. 2/5 * 100 = 40

I think the office worker making $30,000 is in the 40th percentile. and I'm not sure what this ranking indicates.

I thank you for any helpful reply and or different calculation.

Answered by Harley Weston.
Tiling a floor 2012-02-27
From jamie:
how many 16in by 16in blocks would it take to cover a 16ft by 16ft floor?
Answered by Penny Nom.
Romeo throws a pebble at Juliet's wondow 2011-08-22
From Natalie:
There is a picture of Romeo trying to attract Juliet's attention without her nurse who is in a downstairs room, noticing. he stands 10m from the house and lobs a small pebble at her bedroom window (3.5m high). Romeo throws the pebble from a height of 1m with a speed of 11.5m/s at an angle of 60degrees to the horizontal. I have already found that it take 1.74seconds to reach the window and that it does in fact hit Juliet's window however i cannot work out the speed of the pebble when it hits the window! The answer is 9.12m/s but I cannot reach this answer. Hope you can help me :)
Answered by Robert Dawson.
Tiles for a back splash 2011-06-04
From Catherine:
How man 3 11/16 tiles do I need for 28 square foot for a back splash
Answered by Penny Nom.
Why use percentiles? 2011-04-29
From Kenneth:
I need some clarification regarding the word "percentile."

Here is an example and what I know: If an investor had twenty stocks in his portfolio and five of those stocks paid an annual dividend of $200.00 or more, the five stocks are in the 25 percentile.

Why is this word necessary? If my example and explanation is correct, why not simply indicate that 25% of his stocks paid an annual dividend of $200.00 or more?

Answered by Penny Nom.
Tiles on a bedroom floor 2010-10-07
From Rochelle:
John's bedroom floor is square in shape. He used 625 tiles, with a side length of 200 mm, to tile the whole floor. Calculate the area and dimensions of the bedroom
Answered by Penny Nom.
Tiling a floor 2010-05-03
From guadalupe:
how many 16 x 16 inch square tiles fit into a 10 x 10 foot space?
Answered by Harley Weston.
Tiles 2010-04-25
From Pat:
how many 6 inch tiles will I need to purchase for an area that is currently covered with 351 4 inch by 4 inch tiles. Each box of 6 inch tiles states it contains 16 pieces and covers 4 square feet.
Answered by Penny Nom.
Tiling a floor 2010-03-31
From shane:
a floor in a house is 12'6" in width and 10'4" in length. Tiling the floor with each tile 5" on each side. First express the square footage into an improper fraction. Second express the area of each tile in square feet. Third how many tiles needed to tile the floor. Fourth explain how answers relate to real world
Answered by Harley Weston.
How many 20"X20" tiles do I need to cover 90 sq. ft? 2010-03-23
From Karen:
How many 20"X20" tiles do I need to cover 90 sq. ft.
Answered by Penny Nom.
How many 4x4 tiles would I need for 10 sq ft? 2010-01-04
From Chris:
how many 4x4 tiles would I need for 10 sq ft
Answered by Robert Dawson.
Initial Velocity of a Car Plunging Off a Cliff 2009-06-07
From Mimi:
A car fails to take a sharp turn on a flat road and plunges off a cliff. The car lands 65m horizontally and 43m vertically from where it left the edge of the cliff. How fast was the car travelling?
Answered by Stephen La Rocque.
Percentiles 2009-03-21
From Shawn:
For a normal distribution of u=654.00 and o=138.00.
What is the percentile rank for X=426?

Answered by Harley Weston.
A Falling Rock 2008-07-11
From Rita:
This question has 3 parts. If a rock falls from a height of 20 meters on the planet Jupiter, its height H (in meters) after x seconds is about H(x) = 20 - 13x^2 (a) What is the height of the rock when x = 1.2 seconds? (b) When is the height of the rock 15 meters? (c) When does the rock strike the ground? Thank you
Answered by Janice Cotcher.
Tiles on a basement floor 2008-01-31
I have a basement 1000 sq ft I want to purchase tile that are 18x18inches and they are charging 4.15 sq ft how much would it cost since I will need less tiles to cover the area since it's not 12X12
Answered by Penny Nom.
Constantly accelerated motion 2007-10-29
From Priyanka:
A, B and C are three points lying in that order on a straight line. A body is projected from B towards A with speed 3 m/s. The body experiences an acceleration of 1 m/s^2 towards C. If BC =20 m, find the time taken to reach C and the distance travelled by the body from the moment of projection until it reaches C.
Answered by Stephen La Rocque.
The range of a projectile 2007-09-18
From Claudette:
This is a maximum minimum problem that my textbook didn't even try to give an example of how to do it in the text itself. It just suddenly appears in the exercises. Problem: The range of a projectile is R = v^2 Sin 2x/g, where v is its initial velocity, g is the acceleration due to gravity and is a constant, and x is the firing angle. Find the angle that maximizes the projectile's range. The author gives no information other than the formula. I thought to find the derivative of the formula setting that to zero, but once I had done that, I still had nothing that addressed the author's question. Any help would be sincerely appreciated. Claudette
Answered by Stephen La Rocque.
Projectile motion equations 2007-06-12
From Dillon:
Ron throws a ball straight up with an initial speed of 60 feet per second from a height of 5 feet. Find parametric equations that describe the motion of the ball as a function of time. How long is the ball in the air? When is the ball at its maximum height? What is the maximum height of the ball?
Answered by Stephen La Rocque.
Upper Quartiles 2007-01-26
From Jamie:
I see you have a question about Q3 with even numbers but what about odd numbers? I have a problem with 19 numbers 36,45,49,53,55,56,59,61,62,65,67,70,75,81,82,86,89,94,99. Is there anyway the answer could be 81.5 because every time I do it I get 82 and my teacher tells me that is wrong. So in conclusion how do you do it?
Answered by Penny Nom.
Tiles arranged in rows 2007-01-02
From Ann:
Some tiles are arranged in rows so that the number of tiles in each row is 8 more than the number of rows. The same number of tiles can be arranged in 3 more rows than the first pattern with 16 tiles in each row. Find the total number of tiles.
Answered by Stephen La Rocque.
Tiling a floor 2006-06-08
From Marguerite:
A builder is adding a 20' X 28' addition to a house. He has two choices: he can use 8" X 8" tile @ $.98 a tile or 12" X 12" tile @ $1.98 a tile. How much money would he save by using the least expensive choice?
Answered by Stephen La Rocque and Penny Nom.
Outliers in a box and whisker plot 2006-02-19
From A student:
i need help on determining if their is an outlier...i know how to find the median and the lower quartile and the upper quartile..but i don't understand about the outliers....please tell me if their is an outlier in this problem....the numbers are...63,88,89,89,95,98,99,99,100,100
Answered by Penny Nom.
How many tiles do I need? 2005-07-20
From Jeannette:
I am putting up backsplash tile in my kitchen and I need to know how many tiles I would need to use for about 45 square feet using 4x4 tiles.
Answered by Penny Nom.
Percentiles 2004-08-15
From Gary:
Table 1 Selected percentiles for family income in the US in 1992 1 $1,300 10 $10,200 25 $20,100 50 $36,800 75 $58,100 90 $85,000 99 $151,800

Q. The percentage of families in Table 1 with incomes below $58,100 was about?

Answered by Penny Nom.
A square of tiles 2002-08-30
From Rosa:
How do I go about finding a formula for the number of tiles I would need to add to an arbitrary square to get to the next sized square?
Answered by Penny Nom.
Box and Whisker plots 2001-11-19
From Rod:
In our Prealgebra course, we have been studying Box and Whisker plots. Recently, we learned how to decide whether a data point is an outlier or not. The book (Math Thematics, McDougall Littell) gave a process by which we find the interquartile range, then multiply by 1.5. We add this number to the upper quartile, and any points above this are considered to be outliers. We also subtract the number from the lower quartile for the same effect.

My question: where does this 1.5 originate? Is this the standard for locating outliers, or can we choose any number (that seems reasonable, like 2 or 1.8 for example) to multiply with the Interquartile range? If it is a standard, were outliers simply defined via this process, or did statisticians use empirical evidence to suggest that 1.5 is somehow optimal for deciding whether data points are valid or not?

Answered by Penny Nom.
Tiling a floor 2001-05-01
From Sarah:
Cut out of paper or cardboard a quadrilateral having no two sides parallel, no two sides of equal length and no indentations. Can an endless floor be tiled with copies of such a figure?
Answered by Claude Tardif.
The path of a cannonball 2001-01-15
From A student:
Artillerymen on a hillside are trying to hit a target behind a mountain on the other side of a river. Their cannon is at (x, y) = (3, 250) where x is in kilometers and y is in meters. The target is at (x, y) = (-2, 50). In order to avoid hitting the mountain on the other side of the river, the projectile from the cannon must go through the point (x, y) = (-1, 410).

Write the equation for the problem.

Answered by Penny Nom.
Tiling a floor 2000-06-27
From Carolyn Clarkston:
A square tile measures 6 inches by 6 inches. What is the least number of tiles needed to cover a rectangular floor area of 9 feet by 12 feet?
Answered by Walter Whiteley.



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