The maths test was strangely worded so beware. The information tells you how fast people work (pickers, packs, loaders ect) and that you have so many workers (who can do any job) and so many goods. But you need to load x amount of a certain good. How do you distribute the workers?
Well if there is the right number of workers and only the right number of workers than you can work out how many you need for the one requirement and base everything else off that. Because they do not tell you the number of workers you have is accurate (there aren't too many or too few, it is exactly the right amount) going about in generally seems the logical way forward. By that I mean working out what is most efficient given any arrangement of workers then putting the numbers into the equation you form. But when I got told the method for solving the problem they made the assumption that the number of workers is exactly the amount needed.
The face to face interviews were fine. Just have 2 examples of each leadership principle. Why you want to work for the company and some background knowledge.