Looking for help with value costing of inventory

[xeberius]

Hello,

I am writing here since I am having hard time understanding Accounting which I am very much trying to do.

At the moment I am facing a problem with solving an exercise about costing systems. I've been trying different books and websites with guides on how to solve this, however, I have not been able to come up with a solution to this particular exercise.

I would be very thankful if someone could help me understand this.

Thanks!

 

[Becky]

Please show what you have so far, and explain which aspects you need help with