A question regarding FCInv in Schweser notes

I did the question 22 at page 146 in Schweser notes (Equity). It seems that in the answer when calculating FCInv, the depreciation expense 27 is added back. But how come the depreciation expense is not the difference between ending accumulated depreciation and beginning accumulated depreciation, which is 40-30=10?

I haven’t the books, but did the company sell any depreciable assets during the year? If so, the accumulated depreciation associated with those assets would have been removed from the balance sheet.

Yes, you are right! I got it. Thank you very much.

My pleasure.