1. AdamFulton

    finding the biggest number needed that multiples to the numbers in a set

    I am trying to figure out a way to find the biggest "small" number that I need to multiple within a set of numbers... For example using the numbers 1-10 as the set Small number (SN) Largest number (LN) SN times LN 01 10 02 05 03 03 01 09 02 04 01...
  2. C


    Please help me understand how to get the solution to the following: If 7x is a multiple of 210, must x be a multiple of 12? Thank you!
  3. G

    counting multiples

    Hello everybody (Long time no see), is there a formula that allows us to count the multiples of $n$ prime numbers up to a number $S$. What i mean: For example we have three primes $(2,3,5)$. How many multiples (of these three numbers) are up to number $30$ By sequentian steps we have that...
  4. A

    Big and small plates at a party... (maybe multiples or factors.... i'm not sure)

    If anyone, could help me with these I m confused. Thanks! Some fairy cakes are delivered for Janey's party. Janey can use big plates or small plates to put the cakes on. If she uses big plates she can put 7 cakes on each plate with 5 left over. If she uses small plates she can put 5...
  5. A

    Factors and Multiples - 3 bells tolling

    Three bells toll at different intervals. Bell A tolls every 24 seconds, Bell B tolls every 60 seconds and Bell C tolls every 90 seconds. The three bells toll together at 1100 hrs. a) find the number of times all three bells toll together between 1100 and 1200 hours. b) find the number of times...
  6. U

    Faster way to work out multiples

    Hi all, my fractions are not great to be honest but here is my question. Using addition, solve for a and b: 4a-6b=15 6a-4b=10 So I find a common multiple of b, I choose to use 24. 16a-24b=60 36a-24b=60 Now I go ahead and do the addition: 16a-24b=60 -36a+24b=-60 I'm left with: -20a=0 ==...
  7. S

    Residues and Multiples

    really having trouble with these questions, help would be GREATLY appreciated! 1. For each positive integer m define Zm = {0, 1, 2, . . . , m − 1}, the set of all residues modulo m, and define C(m) = { k ∈ Zm | 0 6= k ≡ a3 (mod m) for some a ∈ Z } the set of mod m residues that are nonzero...
  8. J

    Sum of scalar multiples?

    Write the vecor OI--> as a sum of scalar multiples of u and v. (I got 2v-3u, but that's wrong)
  9. M

    SAT multiples problem

    If S is the set of positive integers that are multiples of 7, and if T is the set of positive integers that are multiples of 13, how many integers are in the intersection of S and T? I said there is 1 integer in the intersection, since only 91 is a common multiple of 7 and 13. However...
  10. M

    why is my function so stable at multiples of 22?

    hey everyone, in my never ending quest to find interesting maths based animations i created a trig function but dont understand it. the function is y = sin(x) where x = x+k*sin(x). k has a starting value of 20 and x starts at 180 (or PI). the function iterates once every frame. have a look...
  11. K

    Sums of different multiples

    I am currently studying for the GMAT, and I have run into a problem that confuses me because the correct answer explanation is somewhat vague. How many positive integers less than 28 are prime numbers, odd multiples of 5, or the sum of a positive multiple of 2 and a positive multiple of 4? A...
  12. MoniMini

    Factors and Multiples

    I want to know how to do these 2 types of sums in an easier method...... 1. The smallest 4 digit number exactly divisible by 12, 15, 20 and 35. 2. The least number when divided by 7, 10, 15 and 21 leaves 5, 8, 13 and 19 respectively as remainders. Thanks MoniMini @(^_^)@
  13. Q

    3digit numbers that are multiples of 7 with individual digits that add to 7.

    how can i find all the 3 digit numbers that are multiples of seven with individual digits that add to 7? I've been trying to figure this out using modular arithmetic, but I think I'm doing it wrong.
  14. V

    Trigonometry Equations? multiples of pi?

    how would i go about solving this question? Solve the following equations in the interval [0, 2pi]. Give the answer as a multiple of pi. Do not use decimal numbers. The answer should be a fraction or an integer. sin(t) = -(sqrt(3))/2 t = __?__ pi sin(t) = -1/2 t = __?__ pi
  15. A

    Multiples of any natural number - only with 1,0 as digits

    I read this somewhere recently. For any natural number n, there exists a multiple of n, such that the multiple has only 0 and 1 as it's digits. For e.g for 2, 3, 4, 5, 6 etc we have 10, 111, 100, 10, 1110 etc Any ideas how to go about proving this?
  16. I

    Which multiples of pi should I use to estimate this limit?

    Question: Built a table to estimate limx->0 sin(1/x) It says I have to use multiples of pi, but I don't understand which ones to use in order to estimate the limit? Thanks for any help.
  17. F

    Lowest Common Multiples Question

    Hi all, I've got a question regarding lowest common multiples. I'm not particularly well schooled in math so I was wondering if someone could help me out with this. I have to produce a chart(s) documenting various combinations of integers and their lowest common multiples. e.g. for 2...
  18. A


    Of the numbers 1, 2, 3, . . . , 6000, how many are not multiples of 2, 3 or 5? My answers is: 3000 multiples of 2, 2000 multiples of 3, 1200 multiples of 5, 600 of 10, 1000 of 6, 400 of 15 So 4200 multiples, by adding the first 3 and subtracting the next 3 from the sum, since they have been...
  19. R

    [SOLVED] induction with multiples

    how to prove this 5^{2n}-3^n when n\geq0 i do the base step of proving it works for 0 5^{2(0)}-3^0 =0 and 0\times11=0 zero is a multiple of 11 so assume 5^{2n}-3^n now the inductive step using n+1. Where do i start?
  20. M

    Multiples of 13

    I didn't know where to post this problem so excuse me if this isn't where it should be.. The problem is: Is 54^{103} + 69^{67} a multiple of 13? I have no idea how to go about this problem. Could someone enlighten me to a solution to the problem. (The solution is way more important than the...