







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. 





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

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





GCD 
20130520 

From Julia: Prove that if a and b are coprime integers, the greatest common divisor of a + b and a  b is either 1 or 2. Answered by Penny Nom. 





HCF and LCM 
20130515 

From Kelly: If HCF and LCM of two numbers is 7 and 20 respectively, then the number/s is/are…. Answered by Penny Nom. 





x/200+x/400+x/600+x/800 
20101008 

From Ashishthombre: step by step LCM of x/200+x/400+x/600+x/800 Answered by Penny Nom. 





Least common denominator 
20100213 

From Priscila: 3/8 + 4/5 + 7/3 + 9/10 = ?
Thank you for your assistance.
Priscila Answered by Penny Nom. 





GCD (a + b, a  b). 
20090401 

From Tomas: Let a and b integer and relatively prime. Prove that:
GCD (a + b , a  b) = 1 or 2 Answered by Stephen La Rocque. 





The product of two integers their LCM and their HCF 
20090215 

From Anonymous: Two numbers have LCM = 60. If their product is 180, what is their HCF? Answered by Harley Weston. 





LCM and GCD 
20080522 

From kasirao: Please help me in knowing the proof for the equality,
"The product of two natural numbers is equal to their LCM and GCD" Answered by Penny Nom. 





GCF and LCD 
20080117 

From Peter: I need to know the differences between GCF and LCD. Answered by Penny Nom. 





The realtionship between lcm and gcd 
20071027 

From Brenda: why does multiplying lcm of (n,s) by gcd (n,s) give n times s. when (n,s) are any two numbers? Answered by Penny Nom. 





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. 





LCD 
20070429 

From Jackson: I am having trouble getting the LCD for the following question.
1 3/8 x 8/9= Answered by Penny Nom and Melanie Tyrer. 





LCM and HCF 
20061028 

From Henry: Is there a unique solution to the question: If the LCM and HCF of two numbers are 180 and 15 respectively, what are the two numbers? I got 45 and 60. I got a feeling there are others. 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. 





Least common denominator 
20061004 

From Paulette: Why is the LCD of 3/4 and 4/8 not the product of 4 and 8? Answered by Penny Nom. 





HCF and LCM 
20060805 

From Bharath: The HCF and LCM of polynomials p(x) and q(x) are h and l respectively and p(x) + q(x) = h + l, show that
[p(x)]^{2} + [q(x)]^{2} = h^{2} + l^{2} 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. 





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. 





Greatest Common Factor 
20031108 

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





The HCF and LCM of polynomials 
20030520 

From Charanpal:
Question: Find the HCF and LCM of the polynomials given below. Verify that he productof these HCF and LCM differs from the product of the polynomials, if at all, by a factor of 1  1x^{2} and x^{3} 1
 1  x^{2} and x^{4}  1
Answered by Penny Nom. 





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 least common denominator 
20030121 

From Brittan: Hi there I need help! My name is Brittany and i am in the 6th grade. I need help finding the least common denominator(LCD), and the book says Find the LCM of the denominators and i've done that and then it says write equivalent fractions,using the LCM as the least commonn denominator.The directions say Use the LCD to write each pair as like fractions. and the problem is 1/8 and 5/40. Could u explain how in the word u do this? Thanks a lot Brittany 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. 





Counting CD's 
20011106 

From Jason: An older brother said to his younger brother, "Give me 8 of your CDs, then I will have twice as many as you." The younger brother replied, "No, you give me 8 of yours instead, and then we'll have an equal number." How many CDs does each boy have? Answered by Chris Fisher. 





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. 





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. 





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. 





Tapes and CD's 
20001022 

From Arnold: Nicole has 25 CDs and tapes altogether. When she tries to pair them up, she has 4 CDs left over. How many tapes does Nicole have? Answered by Penny Nom. 





Greatest Common Factor. 
19980109 

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





Mathilde aime la musique et les mathématique. 
20100419 

From Lucas: j'ai un problème pouvait vous m'aider a le résoudre:Mathilde aime la musique et les mathématique.Quand on lui demande combien de CD elle a elle répond "Je ne les ai pas comptés.quand je les groupe 5 par 5 ,il ne m'en reste pas.quand je les groupe 2 par2,il m'en reste 1.quand je les range 6 par 6,il m'en reste 5.je suis surque j'en moins que cinquante."
Peuxtu trouver le nombre de CD de Mathilde?
aider moi svp
ps:je suis en 6ème donc faut pas que se soit trop compliqué Answered by Claude Tardif. 





quel sont les plus grands diviseurs communs? 
20050907 

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

