Tests.cs

using System;
using System.Diagnostics;

class TimedWorker
{
    private readonly Stopwatch timer;

    public TimedWorker()
    {
        this.timer = new Stopwatch();
    }

    public int Work()
    {
        int workDone = 0;

        if (!this.timer.IsRunning)
        {
            this.timer.Start();
        }

        if (this.timer.ElapsedMilliseconds > 5)
        {
            workDone++;
            this.timer.Restart();
        }

        return workDone;
    }
}

static class Tests
{
    static void Main(string[] args)
    {
        var thirtyWorkersResult = TestWorkers(30) / 10.0;
        var fifteenWorkersResult = TestWorkers(15) / 10.0;
        var nineWorkersResult = TestWorkers(9) / 10.0;
            
        Console.WriteLine("30 workers done in " + thirtyWorkersResult);
        Console.WriteLine("15 workers done in " + fifteenWorkersResult);
        Console.WriteLine("9 workers done in " + nineWorkersResult);
    }

    static double TestWorkers(int numberOfWorkers)
    {
        var totalWorkload = new[] { 3740 };
        var timer = new Stopwatch();
        var workers = new TimedWorker[numberOfWorkers];

        for (int i = 0; i < workers.Length; i++)
        {
            workers[i] = new TimedWorker();
        }
            
        timer.Start();
        while (totalWorkload[0] > 0)
        {
            foreach (var worker in workers)
            {
                totalWorkload[0] -= worker.Work();
            }
        }

        return timer.ElapsedMilliseconds;
    }
}