This last exercise brings out the best of your knowledge of the profit structure diagram which you've learned so far.  A friend who was asked to be a shop manager of the school festival came to you asking for some advice.  What kind of advice can you give in order for a success of the Takoyaki shop?  It is recommended to take about 10 minutes break here, to those who just now solved previous problem.  First, drink something and relax a little, and then start solving the problem by using attached files, PDF and Excel.  The answer to this problem is not necessarily just one, therefore, think logically and figure out the right answer by yourself.  It might be a good idea to do it with your friend and to compare them with each other.   The time limit is 30 minutes.  It is finally the end.  Please do your best.