In future you should ask in the Ask the Tutor Forum if you want me to answer your question. This forum is for students to help each other.
The 60,000 is not depreciated!
If you look at the answer carefully you will see that the 240,000 at the start of the year has been depreciated for the full year. Then depreciation on the 60,000 has been removed for the 9 months during which is was not there (so that it only leaves depreciation for the 3 months that it was there).