C) ABC Manufacturing Company purchases 9,000 parts of a machine for its annual requirement, ordering one month's usage at a time. Each part costs Kshs. 20. The ordering cost per order is Kshs. 15 and the carrying charges are 15% of the average inventory
per year. You have been asked to suggest a more economical purchasing policy for the company. What advice would you offer
and how much would it save the company per year? (10 Marks)

First, think of what you know. you know that the number t the end of the equation will need to be subtracted because it is the money he lost from buying the lawn mower. and your first two weeks have negative profit, so that tells you that c and d are wrong. now you can plug any of the weeks into a and b to see which one works. i'll start with plugging week 1 into a.this isn't right because it says your answer for week one should be -90.so now we need to try the same thing with b.this one got you the right answer, (sometimes if you only check with one of the weeks multiple will work so you need to check with more of the weeks, but it worked out fine here)this means that b is the correct answer.let me know if you need more clarification. i hope this : )