removing the last comma in for loops (java)

I'm new to coding and I'm trying to remove the last comma for my last loop.
It would be great if I can get help!

import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner dev = new Scanner(System.in);
int num1, num2;
num1 = dev.nextInt();
num2 = dev.nextInt();
int numa = 1;
System.out.println();
for (numa = num1; numa <= 100; numa++) {
if (numa / num1 == 1 && numa % num1 == 0)
System.out.print(numa);
else if (numa % num1 == 0)
System.out.print("," + numa);
}
int numb = 1;
System.out.println();
for (numb = num2; numb <= 100; numb++) {
if (numb / num2 == 1 && numb % num2 == 0)
System.out.print(numb);
else if (numb % num2 == 0)
System.out.print("," + numb);
}
int numc = 1;
System.out.println();
for (numc = num1; numc <= 100; numc++) {
if(numc / num2 == 2 && numb % num2 == 0)
System.out.print(numc);
else if(numc % num1 == 0 && numc % num2 == 0)
System.out.print(numc + ",");
}
}
}

Following the comment of @Lino, change your last loop to:

for (numc = num1; numc <= 100; numc++) {
if(numc / num2 == 2 && numb % num2 == 0)
System.out.print(numc);
else if(numc % num1 == 0 && numc % num2 == 0){
if(numc < 100) 
System.out.print(numc + ",");
else
System.out.print(numc);
}
}

A better way would be to add the numbers to a list (for example numbersToPrint) and then using Collectors.joining():

String output = numbersToPrint.stream().map(i-> String.valueOf(i)).collect(Collectors.joining(","));
// output: 1,2,...,100

Or using StringJoiner:

StringJoiner sj = new StringJoiner(",");
sj.add(String.valueOf(1)).add(String.valueOf(2));
String output = sj.toString();
// output: 1,2

Or using String.join:

String output = String.join(",", String.valueOf(1),String.valueOf(2));
// output: 1,2

I would recommend the following as much more standard, and therefore, for long-time java programmers, readable (uses i for integer loop counter, prefers counting to < instead of <=, simplifies math expressions):

    System.out.println();
boolean lastWasEqual = false;
for (int i = num1; i < 101; i++) {
boolean isHalf = (2 * i == num2);  // a/b = 2 <=> 2a = b
boolean isEqual = (i == num2);     // (a%b) = (b%a) = 0 <=> a = b
if (isHalf || isEqual) {
if (lastWasEqual) {
System.out.print(","); 
}
System.out.print(i);
lastWasEqual = isEqual;
}
}

The idea here is that we only output a , once we know that (a) it was ready to be printed (lastWasEqual) and (b) there will be output after it (so that "the last comma" is never printed).

By looking at the math, you can see that isEqual will be true at most once, and isHalf will also be true at most once. And it is easy to see when they will be true. So there is no need for loops:

 System.out.println();
boolean willReachEqual = (num1 <= num2) && (num2 <= 100);
boolean willReachHalf  = (num1 * 2 <= num2) 
&& ((num2 % 2) == 0) && (num2 <= 200);
boolean willReachBoth = willReachEqual && willReachHalf;
System.out.println(
(willReachHalf ? (num2 / 2) : "") + 
(willReachBoth ? "," : "") + 
(willReachEqual ? num2 : ""));