Hard Question: regarding inventory and cost

[truthfulone]

A hardware store sells approximately 10 000 light bulbs a year. The owner wishes to determine how large an inventory of x (thousand) bulbs should be kept to minimize the cost for inventory. The carrying cost for the bulbs is $40/1000 while the paperwork for ordering is $12 per order. The variable reorder costs are $24/1000

a) If x (thousand) bulbs are ordered each time, find the yearly cost for ordering the 10 000 bulbs into inventory.
b) On the average his inventory is x/2 (thousand) bulbs. Find the total cost for inventory.
c) Find the size of each order to minimize the cost for inventory.

This question is confusing.
But here is my try:

$40/1000 = x/10 000
x= $400

So, the function is probably, \(\displaystyle 400+\)\(\displaystyle \frac{12 (10 000)}{x}\)

Now, am I on the right path? I think I understand the problem correctly. But please help. Thanks.

 

[truthfulone]

Actually, I found that the answer to part a is $120. But can anyone help me with the rest? Thanks.

 

[truthfulone]

why isn't anyone answering this?

 

[stapel]

why isn't anyone answering this?

As you read in the "Read Before Posting" thread that you read before posting the above, "There is no paid staff waiting on-hand to give instant replies. Many of the volunteer tutors have "real" jobs, and they all have to sleep from time to time...." For instance, I've been busy today (well, yesterday, now) taking my child to a doctor, to violin lessons, and to martial arts, in addition to helping him with his schoolwork and attending to my own tasks. :shock:

I apologize that none of the topic-qualified volunteers happened to be available within the window you needed. To obtain the guaranteed instant (or fast) replies you require, you will need to contract with a service which offers such. :idea:

My best wishes to you in your studies.

Eliz.