Consider:
int[][] multD = new int[5][]; multD[0] = new int[10];
Is this how you create a two-dimensional array with 5 rows and 10 columns?<
Try:
int[][] multD = new int[5][10];
Note that in your code only the first line of the 2D array is initialized to 0. Line 2 to 5 don't even exist. If you try to print them you'll get null for everyone of them.
null