Recent content by rsala004

if you are given an amount of cents, and a set of coin denominations...how can we tell if its impossible to amount to exactly the given amount of cents? for example say we want to gather 8 units of value but only have coins with denomination 3 and 7, thus its not possible to make a combination...

if we have 6 and 9 and we break them down to sets of prime factors {2,3} , and {3} if the intersection of the 2 sets is empty..does this mean that numbers have no common factors? or in more specific to my interest... if we have P and Q and we have their sets of prime factors, if the...

the actual problem I am trying to solve is a bit different .. but similar problem i think (?) okay, so with these problem settings below (U being some integer to represent x's maximum value) I can try to solve for x by setting up and the solutions are when both x and k are integers. ah i...

no no, i mean some other defined lowerbound and upperbound. for example, 0 to 1000000.. otherwise i assume there would be endless solutions. --- I guess in my case i want to exclude negatives from k (since my boundary is positive), and include 0. --- I read some more and I found this : So...

if we are given something of the form where we are given a and b ...how can x be solved for ? what if we are given a range for which x has to fall within? something like 0 <= lowerbound <= x <= upperbound -- I have thought about this a little while i came up with that with k a positive...

this problem has been on my mind... how many permutations can you make with 30 'A's and 30 'B's or rather the same question, how many unique numbers can be made from 30 1s and 30 0s any ideas? (excluding permutations that look identical) thanks

http://www.spoj.pl/problems/SAMER08F/

this is to figure out formula for how many squares you can find in a nxn box. 12+22+32+...+N2 Can someone show steps to how a simplified formula can be found? ( i only know the concept of induction, not how to do it really..) it is (n)(n+1)(2n+1)/6 , but how is this accomplished...

I am trying to make a basic little program where i can input a large set of texas holdem hands (2 cards) and check to see how Unlikely/likely these cards were to be dealt. (to show that no tampering was done...ie. show its random enough) For example, it is VERY unlikely that a player receives...

thank you

Lets say you have a bunch of projects to do, says project 1,2,3,4,5. You don't have to do them all, in fact you don't have to do any of them...and the order you did them in has no effect on how they come out. how many ways can this be done? examples, 12, 1234, 234 or no projects at all edit...

(1+2+...n)^{2} = 1^{3}+2^{3}+...n^{3} \frac{n^{2}(n+1)}{4}^{2} = 1^{3}+2^{3}+...n^{3} how do you simplify the right side to show that they are equal?

if you have an array with size 1000000, would selection sort be feasible on a everyday laptop computer, or just too large? I imagine it would take (1Million)2/2 loops to complete the sort

not really math but wondering if someone is clever enough to know answer to this.. Some of you may know that if you pick (almost) any integer and add its reversed digits to it, and repeat this process ..you will eventually get a palindrome. for example: # 56 becomes palindromic after one...

lol so obvious i didnt notice.