







GCD 
20171125 

From A student: Suppose a,b, c are integers such that gcd(a,b)=gcd(a,c)=1. Show that gcd(a,bc)=1. Answered by Penny Nom. 





Abstract algebra 
20171125 

From A student: Suppose a,b, c are integers such that gcd(a,b)=gcd(a,c)=1. Show that gcd(a,bc)=1. Answered by Penny Nom. 





Baseball Cards 
20170420 

From Raquel: A minor league baseball team gave away baseball cards to each person entering the stadium. One group receives 28 baseball cards. A second group received 68 baseball card. If each person entering the stadium receive the same number of cards, what was the greatest possible number of baseball cards that each person could have received? Answered by Penny Nom. 





How can he raise his average to 90? 
20151229 

From Raj: Harris has an 87 in a class where daily works count 20%, quizzes count 20% and tests count 60%.
If there are only two test scores what must the score on his second test to raise his average to 90? Answered by Penny Nom. 





A circle and a chord 
20150207 

From Dakota: If the diameter of a circle is 48 cm, find the shortest distance from a chord of length 34 cm to the center of the circle Answered by Penny Nom. 





The greatest common divider of n^23n1 and 3 
20140309 

From Rimoshika: determine the greatest common divider (n^23n1,3) Answered by Penny Nom. 





A contest with 31 people 
20130906 

From Kevin: There is a contest with 31 people and only one winner each week.
We play for 17 weeks.
What are the odds of winning at least one week?
The chances of winning each week are independent from previous weeks. Answered by Robert Dawson. 





A shortest distance problem 
20130328 

From LYNDELL: I have a right triangle and know the length of all sides. How do I calculate the shortest distance from the vertex of the 90 degree angle to the hypotenuse? Answered by Penny Nom. 





The shortest chord 
20120726 

From ANJANA: AB is a diameter of a circle.
C is a point in AB such that CA = 9 cm and CB = 25 cm.
Find the length of the shortest chord through C. Answered by Chris Fisher. 





Ordering fractions 
20110817 

From Myon: My problem is putting fractions from least to greatest and they are 1/4 2/5 1/3 4/6 1/2 8/9 3/4 1/1 2/6 1/10 thanks Answered by Penny Nom. 





A normal distribution problem 
20101202 

From Racquel: I am stuck on this question. I am not sure if using the z score will help
me get the answer I need. Here is the question?
The average length of time per week that students at this university spend
on homework is normally distributed with a mean of 18 hours and a standard
deviation of 3 hours. If Diane spends more time on homework each week than
75% of students, what is the minimum time she must spend? Answered by Penny Nom. 





The volume of a test tube 
20100520 

From Nick: A maths question. I have a test tube (basically a cylinder but with a rounded
bottom end) and the measurements are: the diameter or width of the tube is
31mm and the total length of the whole tube is 204mm. The question is:
(a) what's the volume of this test tube (rounded to the nearest cubic mm) and
(b) what's the capacity of this test tube (rounded to the nearest mL).
I need to show the full mathematical workings out of the two, not just the
answer. The problem is the circular bottom end of the tube, it isn't flat, that
would make it rather "easy"or straightforward but this is a halfcircle
(like all test tubes are)!! Answered by Penny Nom. 





The rejection region 
20100501 

From Mong: In Tests of Hypothesis, what is the decision when the test statistic we compute from the sample information is exactly equal to the critical value? that is, we reject null hypothesis or do not reject it?
Thanks! Answered by Chris Fisher. 





The test for some disease is 99% accurate 
20100224 

From baaba: Assume that the test for some disease is 99% accurate. If somebody tests positive for that disease, is there a 99% chance that they have the disease? Answered by Chris Fisher. 





Ordering fractions 
20090915 

From stacy: I need help with listing fractions from the least to greatest. last problem of math is 5/6,7/9,23/27,13/18? Answered by Penny Nom. 





Order from least to greatest 
20090915 

From myra: which list of number is ordered from least to greatest? A.) 0.035,0.35,2/5,2.5 B) 2.5,2/5,0.35,0.035 c)2/5,0.35,2.5,0.035 D) 0.035,2.5,0.35,2/5 Answered by Penny Nom. 





Highest Common Factor of Two Polynomials 
20090728 

From Nazrul: If x+a be the h.c.f. of x^2+px+q and x^2+mx+n, how can I prove that (pm)a=qn. Answered by Robert J. Dawson & Janice Cotcher. 





The ratio test 
20090306 

From Haley: Use the ratio test to determine whether the series in convergent or divergent.
(2/5)+(4/10)+(8/15)+... Answered by Harley Weston. 





(12+8)/2x42= 
20090130 

From Susan: (12+8)/2x42= Answered by Harley Weston. 





The vertical line test 
20090126 

From bob: what is a Vertical line test Answered by Stephen La Rocque. 





Function or Not? 
20080822 

From Katie: Determine whether y is a function of x:
[(x^2)y](x^2)+(4y)=0
....thx Answered by Janice Cotcher. 





What is the greatest area she can have for her garden? 
20080512 

From angie: Mary has 12 wood boards, each board is 1 yard long. She wants her garden to be shaped like a rectangle. What is the greatest area she can have for her garden? Answered by Penny Nom. 





The shortest distance from a point to a line 
20080403 

From Katherine: How do I find the shortest distance from the point (3,5) to the line x = 2 Answered by Stephen La Rocque. 





What point on the graph y = e^x is closest to the origin? 
20080303 

From elvina: What point on the graph y = e^x is closest to the origin? Justify your answer. Answered by Stephen La Rocque. 





Average Yearly Percentage Change 
20080110 

From Ray: It's about average test scores over a three year span. If the scores were:
2005 52.6%
2006 42.5%
2007 45.5%
What is the average amount they changed each year in three years? Answered by Stephen La Rocque and Harley Weston. 





The shortest distance to a line 
20080104 

From nana: 3y+4x12=0 is the equation of the line AB on a graph......the line AB joins both y and x axises together.....point A is on y axis and its value is 3....point B is on x axis and its value is 4.....Question : from point O(0,0).find the point ont the line AB Answered by Stephen La Rocque. 





Which expression gives the greatest value? 
20071218 

From Jordan: 'Look at these expressions'
n2, 2n, n(squared), n over 2, and 2 over n (sorry I can't type the expressions out)
A) Which expression gives the greatest value when n is between 1 and 2?
B) Which expression gives the greatest value when n is between 0 and 1?
c) Which expression gives the greatest value when n is negative?
As you can see, this IS ONE question split in to three parts lol!
Can you tell me how I go about tackling this question? I lost marks on the test because of not
understanding the question. Answered by Stephen La Rocque. 





A ttest 
20071120 

From Rachel: I am wanting to use the ttest to find if temperature over a period of 5 days was significantly different to the mean temperature for that time of year. So i want to compare expected temps to actual temps. The problem is that because the expected temperature is the same for the 5 days it gives me a standard deviation of zero. Does this mean the ttest cannot be used because the ftest can't be calculated. If so is there an alternative test? Answered by Harley Weston. 





A 5digit whole number 
20071119 

From sunjoo: a friend tells you to think of a 5digit whole number. then do the following in order : multiply the number by 2. add 200 to the result. divide the result by 2. subtract 100 from the result. what is the greatest number you can get as an answer? Answered by Stephen La Rocque. 





Measurements on a test tube 
20071030 

From Bruce: I figure that the surface area (SA) of a round bottom test tube
can be determined by the equation SA = 2pi*h*r
where r is the radius of the hemispheric bottom & column part, and
h is the height (h) at any point upwards from the bottommost portion
in the center of the tube.
I haven't been able to come up with an equation yet for the circumference
of such a test tube at any point upwards along the tube based
on the height in its center or on the distance along the outside
of the tube. Answered by Harley Weston. 





The odds of winning a contest 
20070729 

From Kevin: I have been asked by a customer in Missisauga to track down some odds of
winning a contest. In this contest, the last 4 digits of the winner's
driver's license number have to match the last 4 digits of a Harley VIN
number. There are 200 people maximum allowed into the drawing, 10,000 total
possible VIN combos. Would the odds be 1:50 or something other than that? Answered by Harley Weston. 





Students in rows 
20070517 

From Ashi: the student of three classescan be made to stand into rows having same number of students. there are 24,36 and 60 students in the classes. how many maximum number of student will stand in each row. Answered by Stephen La Rocque. 





A hypothesis test 
20070409 

From Katrina: I have already tried to do this problem but im having a very had time with
it. Can you please help me.
Glamour Magazine sponsored a survey of 2500 prospective brides and
found that 60% of them spent less than $750 on their wedding gown.
Use a 0.01 significance level to test the claim that less than 62% of brides
spend less than $750 on their wedding gown. How are the results
affected if it is learned that the responses were obtained from magazine
readers who decided to respond to the survey through an Internet Web
site? Answered by Penny Nom. 





Greatest common divisor 
20070314 

From Marie: How do I prove this?
Let h be the greatest common divisor of the positive integers a and b.
Show that there exist integers p and q (not necessarily positive) such that
pa + qb = h.
Thanks Answered by Penny Nom. 





Greatest common factor 
20070126 

From Alexis: What is the greatest common factor of 52,and 100? Answered by Penny Nom. 





Answer to skill testing question 
20070118 

From Mike: This question was on a ballot. Is the right answer 36 or 1? 5+21X6= Answered by Stephen La Rocque. 





A statistics question 
20070107 

From Rick: For many years TV executives used the guideline that 30 percent of the audience were watching each of the primetime networks and 10 percent were watching cable stations on a weekday night. A random sample of 500 viewers in the TampaSt Petersburg, Florida, area last Monday night showed that 165 homes were tuned in to the ABC affiliate, 140 to the CBS affiliate, 125 to the NBC affiliate, and the remainder were viewing a cable station. At the 0.05 significance level, can we conclude that the guideline is still reasonable? Answered by Penny Nom. 





Skill Testing Question 
20061220 

From Tonia: Skill Testing Question: Multiply five(5) x four (4) Add twenty two (22) Divide by two (2) Subtract six (6) Answered by Penny Nom. 





BEDMAS? 
20061129 

From john: I won a contest and they have a confusing format for the STQ. here it is: 11 (+) 44 (x) 2 () 10 (%) 25 I've never seen brackets around the operands and wondering how to treat it. I fear they want me to answer the question left to right as the answer is 4 if I use BEDMAS I get 98.6 (which clearly sounds wrong for what they want) any thoughts? Answered by Stephen La Rocque. 





The greatest common factor 
20061017 

From Myrna: What is the greatest common factor of 49,164 and 80,860 Answered by Stephen La Rocque. 





16X27+32÷426 
20060820 

From Amanda: The question was 16X27+32÷426. Answered by Stephen La Rocque. 





The greatest common factor of two numbers 
20060716 

From Fadwa: What is the greatest common factor(GCF) of the following algebraic expressions? 1680 and 6048
Answered by Stephen La Rocque. 





GCD 
20060320 

From Jana: How can i prove:
if gcd(a,b)=1 then gcd(a+b,ab)=1 Answered by Penny Nom. 





Highest common factor 
20060206 

From Sajid:
1.A rectangular field has dimensions 156 m and 84 m. It is to be fenced with wire netting supported by stakes, equally spaced, a stake being placed at each corner of the field. What is the greatest possible distance between any two stakes, given that it should be more than 2 m and less than 8 m?
2. What is the length of the side of the largest square tile which can be used to cover a floor 525 cm long by 275 cm wide without leaving a gap?
3. Find the greatest number which will divide 140 and 249 to leave remainders 8 and 18 respectively?
4. Find the greatest number which will divide 304 and 298 so as to leave remainder 4 in each case.
Answered by Penny Nom. 





GCF, LCM, primes and the ladder method 
20060107 

From Linda: How would I teach both finding the GCF and LCM with prime factors...I recall the ladder method vaguely.??? Answered by Penny Nom. 





The shortest distance from a point to a line 
20050330 

From carly: Find the shortest distance from the point (15, 2.5) to the line 5x+6y=30. Answered by Penny Nom. 





A standard deviation test 
20041109 

From Karen: How do you compare to see if a sample standard deviation is different than the population standard deviation? I know how to compare means, but not standard deviations. Answered by Penny Nom. 





GCD and LCM 
20041031 

From Cartalina: how do you calculate the "positive difference between the GCF and LCM of two numbers"? Answered by Penny Nom. 





GCD (a + b , a^2  ab + b^2) 
20040827 

From Carol: Let a and b integer and relatively prime. Proof that:
GCD (a + b , a^2  ab + b^2) = 1 or 3 Answered by Penny Nom. 





The pvalue 
20040725 

From Kathy: Ms. Lisa Monnin is the budget director for the New Process Company. She would like to compare the daily travel expenses for the sales staff and the audit staff. She collected the following sample information.
At the .10 significance level, can she conclude that the mean daily expenses are greater for the sales staff than the audit staff? What is the pvalue?
Having problems finding the pvalue & unsure of the formula.
Kathy Answered by Penny Nom. 





Greatest Common Factor 
20031108 

From Beth: How do you use the Greatest Common Factor in addtion and subtraction of fraction? Answered by Penny Nom. 





A skill testing question 
20030427 

From Allan: it is a contest Labatt Blue can you please give me the answer some people are saying 154 and some 34 Answered by Leeanne Boehm and Harley Weston. 





38 minus 10 plus 12 divided by 4 times 16 
20030423 

From James: please help me work this math problem 38 minus 10 plus 12 divided by 4 times 16 Answered by Harley Weston. 





Some 5th grade problems 
20030124 

From Sabrina:
[What is the greatest common factor of 20,28, and 36?] next problem is [5k+7(k+8)= ] next problem [Curtis simplified 0.8 divided by 0.2 x 0.04 and got 10. Latoya Simplified and got 1.6. is either correct? Can you explaine how you got the answer please.] Answered by Penny Nom. 





The Praxis II test 
20020709 

From A student: I am taking the Praxis II test and I can't seem to answer certain styles of questions. Please help!!!!!!  In a class of 29 children, each of 20 children has a dog and each of 15 has a cat. How many of the children have both a dog and a cat?
 If there are exactly 5 times as many children as adults at a show, which of the following CANNOT be the number of people at the show? a. 102 b. 80 c. 36 d. 30
 In order to estimate the population of snails in a certain woodland, a biologist captured and marked 84 snails there were then released back into the woodland. Fifteen days later the biologist captured 90 snails from the woodland, 12 of which bore the markings of the previously captured snails. If all of the marked snails were still active in the woodland when the second group of snails were captured, what should the biologist estimate the snail population to be based on the probabilities suggested by this experiment? a. 630 b. 1,010 c. 1040 d. 1080.
Answered by Paul Betts. 





Math test 
20020628 

From Dustin: I have a really important placement test to take in 2 weeks. I need to have a strong comprehension of algebra and I have't taken a math class in about for years. I'm 24 and am going back to school. I want to get ahead and into math 96, and must pass this test to do that. Do you know of a book or a wab site that can teach me a few formulas that will give me the edge I need. If I have the right text for the job i'll study day and night to pass. Answered by Leeanne Boehm. 





A test drive 
20020423 

From Jennie: At 9 A.M. a test car driving at a constant speed passes a marker 50 miles from it's starting point. At noon the car is about 130 miles from the marker. If the test drive ends at 1:30 P.M., how far will the car be from its starting point? Answered by Penny Nom. 





The bleep test 
20020413 

From Lorraine: I am currently undergoing training and have asked about a fitness test called the bleep test. The bleep test involves running continuously between two points that are 20m apart. These runs are done in time to a prerecorded bleep sounds on a prerecorded audio cassette. The time between the recorded bleeps decrease after each minute. I would like to do my own personal version for training but I have to work out the following before doing this: I need to find out the time inbetween the beeps at least for the first level so I can work out the difference for the other levels: The information given to me for the first level is : A 20 meter run at 8.5km/hr (how long would it take?) Please let me know if there is any way in working out this query with the information given. Answered by Leeanne Boehm. 





Testing a hypothesis 
20020314 

From A student: A large distriutor of cosmetics has kept his outstanding accounts receivable to a mean age of 18 days over the past year. This average is considered a standard by which to measure the efficiency of the credit and collections department. Management wishes to check if receivables in the current month is over standard and will do this at a significance level of 0.50. A random sample of 100 accounts yields an average of 20 days with a standard deviation of 9 days. what should management conclude? Answered by Andrei Volodin. 





350 students took the math A exam 
20020222 

From Jim: at a high school 350 students took the math A exam. 82% passed the test. 40 students that failed the exam in june, took the exam in August. 70% of this group passed the August test. How many of the original 350 students have passed the exam before september? Answered by Paul Betts and Penny Nom. 





Normal distribution 
20020121 

From Danielle: A teacher gave a test on which the students' marks were normally distributed, but the results were pathetic. The mean was 52% and the standart deviation was 12%. The teacher decided that the top 10% of the students should get A's, the next 20% should get B's, the next 40% should get C's, the next 20% should get D's, and the bottom 10% should get F's. To the nearest percent, what are the cutoff marks that will result in an A, B, C, D, and F? Answered by Penny Nom. 





Reduce 79,537/3,623,420 
20011213 

From Eliana: How do you reduce 79,537/3,623,420. Answered by Claude Tardif. 





A function or not a function? 
20011018 

From Christian: Which are the following are not functions?  y = x^{2}
 y = x^{3}
 x = y^{2}
 y = 3
Answered by Leeanne Boehm. 





Scoring a college placement test 
20010926 

From Carmen: A college placement test consist of 75 multiplechoice questions, each having 5 possible answers. The exam is scored by subtracting from the number of correct answers onequarter of a point for each question answered incorrectly. If a person answers every question on the exam and scored 45, how many questions were answered wrong? Answered by Penny Nom. 





GCD and LCM 
20010924 

From David: Find the GCD adn LCM of the following numbers. Assume p 2 to the power p, 3 to power q, 5 to power r and 2 to power q, 3 to power r, 7 to power p Answered by Penny Nom. 





The shortest distance from a point to a line 
20010605 

From Kat: Find the shortest distance from the given line. Round to the nearest tenth. (2,1) and x+5y+20=0 Answered by Penny Nom. 





SPRT 
20010524 

From A researcher: I have a medicalpharmaceutical study that says: SPRT (something to do with Secuential and Truncated). Do You know what it means S.P.R.T. and what it is? Answered by Ejaz Ahmed and Penny Nom. 





Greatest Common Factor 
20010509 

From Nicole: What is the Greatest Common Facter for:
126,261 1008,1080 546,1995 128,256 and 255,256 Answered by Penny Nom. 





A sequence defined recursively 
20010501 

From A student: A sequence s is defined recursively as follows: s_{0}=1 s_{1}=2 s_{k}=2s_{k2} for all integers  Compute s2,s3,s4... to guess an explicit formula for the sequence sk. Answered by Penny Nom. 





Is there an odd and even function? 
20010302 

From Saima: Is there a function that is both even and odd at the same time? In other words, is there a function that can pass the yaxis, xaxis, and origin symmetry test? Answered by Claude Tardif and Penny Nom. 





Greatest common factor 
20010117 

From A teacher: I'm a teacher at a local Middle School and I would like the answers for the following questions. What is the greatest common factor for.. 546 and 780 156 and 732 . . . Answered by Leeanne Boehm and Penny Nom. 





A pair of numbers whose GCF is 28 
20001227 

From John: Name 2 different pairs of numbers whose GCF is 28. Answered by Penny Nom. 





An infinite series 
20001216 

From John: summation(n=1 to infinity)[n sin(1/(2n))]^{n} Answered by Harley Weston. 





Eligibility in a contest 
20000314 

From Ken Rabley: Hi, hoping you can help. Dispute among coworkers. Tell me, what is the correct answer to the following question: 1936 + (2406/4812) x (4756  3256) + 1250 Seems this is the question for eligibility in a contest...We have come up with various solutions, all which may be correct. Answered by Penny Nom. 





Factoring, primes, GCF and LCM 
20000227 

From Ruth Kroek: My son is in grade seven, he has to do a Factoring Booklet the areas covered are:  Prime #'s
 Composite #'s
 Rainbow Factoring
 Finding Multiples (consecutive multiples)
 Finding GCF of 23 numbers uning Rainbow factoring
 Finding LCM of 2 numbers using consecutive multiples
 prime factor trees
 prime factor ladders
 finding GCF of 2 numbers using Prime number Method
Although his text 'Math Power' gives some information, we are at a loss .. Answered by Penny Nom. 





Two contest problems 
19990414 

From Bruce Baldwin: We have students that are preparing for the Pythagoras Contest which is a nation wide Grade 6 math challenge. In the preparatory tests we have run into several questions that we can not understand. Is there anyone who can help us?  If 1 * 9 = 0, 9 * 8 = 72, 2 * 8 = 9, then 9 * 9 = ?
 ...
Answered by Judi McDonald and Walter Whiteley. 





Greatest Common Factor. 
19980109 

From Percy Stribling: how do you figure out what the greater common factor is? Answered by Penny Nom. 





quel sont les plus grands diviseurs communs? 
20050907 

From Sylvain: quel sont les plus grands diviseurs communs? Answered by Claude Tardif. 

