There seems to be a mix up in the solution. The workings for Year 2020 seems not correct most especially the number of yatchs and boat sold.
The data in the table shows 25 units of yatch were sold while 533 units of boats were sold in year 2020 but in the solution 640 units of boats and 30 units of yatchs were used respectively
Could anyone provide more insight on this or it was just an error or mix up that was not discovered?