Assuming decoration for the shop as a improvement in the adjusted trading profit

In the only example available in the chapter 4 for adjusted trading profit for individuals, I assumed the amount of 2,200 for decorating the shop as an improvement whilst solving for the answer and, my answer made a difference of exactly the amount of 2,200 comparing with that of the tutor’s answer. We were told by the tutor herself that it is a long debate on deciding the decoration as an expense or an improvement so, we have to note it in the answer telling the examiner what we’re assuming the amount as. So, should I be confident telling myself that I got the answer in the first try without watching that how the tutor did it?