hi friends, im a newbie at C, im trying to code for a program which cud return all prime numbers in a specific range. its returning the results with an error, which is , it also includes the products of two prime numbers in results, for example 15=3*5 and 21=3*7 my code is --------------------------------------------------------- Code: #include<conio.h> #include<stdio.h> void main() { clrscr(); for (int i=1;i<=300;i++) { for(int j=2;j<=i;j++) if(i%j==0 ) break; else { printf("\t%d ",i); break; } } getche(); } -------------------------------------------------- Result: 3 5 7 9 11 13 15 17 19 21 23 ................. kindly guide me where the problem resides. which is letting 15,21 etc in output.

Here is the code for finding a prime number in a specified range. Code: #include <stdio.h> #include <math.h> // The range of numbers where you want to look for prime numbers #define RANGE_MIN 2 #define RANGE_MAX 100 void main(void) { int i,j,sq,is_prime; for(i=RANGE_MIN;i<=RANGE_MAX;i++) { is_prime = 1; sq = sqrt(i); // calculate the square root for(j=2;j<=sq;j++) { if(i%j==0) is_prime = 0; } if(is_prime) printf("%d, ",i); } } Also checkout this thread http://www.go4expert.com/showthread.php?t=2049