The point in this exercise is to find out what sort of questions you ask and the assumptions you make..... Why? Because working at owlstone is not like a traditional tech company, the requirements are not always known as owlstone are developing cutting edge products and they really don't know the answers until they bump into the problems that need solving..... It's not a task to come up with a perfect solution, it's a task to get candidates to question and assume and to see how they tackle these.