Why do you need to combine the 2 loops into one?
Do you know the range of numbers that can be in your arrays?
you just need 3 loops
so the process would be;
declare a temporary 2 dimensional array for storage
1 dimension needs to be as many elements long as your 2 arrays have in total. The other is 2 elements long.
Loop through array 1
look at an element.
Look in the temporary array tosee if this number has been recorded yet
If no, add it to the temporary array, and score 1 in the second column
If Yes, add 1 to the number in the second column (the total number of instances of this number in the array)
Repeat this to loop through array 2
Loop thru the temporary array, to find out which number has the highest score inthe second column. i.e. which is the modal number.
this is all basic stuff to do in c#, or vb.net, so if you can write this code in one, you can write in the other. (in fact, iirc, MSDN has examples for most of the functions in C# and VB.net, so look at your vb code, adn go to help when u get stuck !)
K