Would you be expected to do all the math for this case? It is not hard, but somewhat time consuming. I can understand if they expect you to calculate 1 energy source for task 3, but then to do the same calcs for the all the other energy others to me seems like a waste of time. Surely showing you can do the math and have correct reasoning to get one energy source is enough. Is this common with other cases?
Also, data sheet A shows 27.1% on the chart, but clearly this does not add up to 100% with the other segments. In the solution I can see they have used 27.2% (so does add to 100% Is this deliberate, are they expecting you to notice this during the interview?