







Gravel for a French Drain 
20200417 

From Ray: Hello,
** I am wanting to add 2 French Drain's in my yard. The 1st drain will be 25 ft. long, 8 in wide and 18 in deep. The pipe I'm using is 4in. in diameter. I'm trying to figure out how many yards of clean gravel I will need for this project?
** The 2nd French Drain will be 100 ft in Length, 10in wide and 18 in deep. I will also be using the 4in in diameter pipe for this drain. I am needing to see how many yards of clean gravel, I'll need for this drain?
Any assistance would be greatly appreciated!! Thank you!! Answered by Harley Weston. 





4" x 4" square tiles 
20190918 

From Jill: how many 4" x 4" square tiles would I need for 50 square feet? Answered by Penny Nom. 





An egg falls from rest 
20180510 

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 
20160305 

From joanne: How many floor tiles 20x20 inch do I need for area of 8x 12 ft.? Answered by Penny Nom. 





Tiling a room 
20150216 

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 
20130320 

From Primadonna:
Hi,
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 
3140 
2 
3150 
5 
3160 
10 
3170 
19 
3180 
30 
Which 10minute interval contains the first quartile?
(1) 31–40
(2) 41–50
(3) 51–60
(4) 61–70 Answered by Penny Nom. 





Tiling a floor 
20130318 

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 
20130215 

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 
20121017 

From Kenneth: Question from Kenneth:
Hello:
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 
20120227 

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 
20110822 

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 
20110604 

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? 
20110429 

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 
20101007 

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 
20100503 

From guadalupe: how many 16 x 16 inch square tiles fit into a 10 x 10 foot space? Answered by Harley Weston. 





Tiles 
20100425 

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 
20100331 

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? 
20100323 

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? 
20100104 

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 
20090607 

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 
20090321 

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 
20080711 

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 
20080131 

From ORIETTA: 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 
20071029 

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 
20070918 

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 
20070612 

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 
20070126 

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 
20070102 

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 
20060608 

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 
20060219 

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? 
20050720 

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 
20040815 

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 
20020830 

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 
20011119 

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 
20010501 

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 
20010115 

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 
20000627 

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. 

