using System;
using System.Collections.Generic;
using System.Linq;
using System.Text.RegularExpressions;
 
public class Test
{
	public static void Main()
	{
		var packageSize = "4/8.75LB";
		//var packageSize = "LB"; // => 'LB' did not match the regex.
    	var result = Regex.Split(packageSize, @"(\d)(?=\D*$)");
    	if (result.GetLength(0) != 1) { // We have found a match
        	foreach (var s in result)
	        	Console.WriteLine(s);
    	}
    	else
    	{
    		Console.WriteLine($"'{packageSize}' did not match the regex.");
    	}
	}
}

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