# Thread: Word Problem: Month of Supply

1. ## Word Problem: Month of Supply

A book I am reading through lists the formula for months of supply in a word problem as

(total units)/(units removed)*12

For instance you have a stock of 2,000 PS3s and you removed 500 from your inventory for the year. What is your month of supply for PS3s? 2,000/500*12=48 months of supply. In other words Month of supply is the rate rate at which which you are selling PS3s, if you were to purchase no more to add to your stock, it would take 48 months to sell what you currently have at this current rate.

Problem: I dont understand why we are using division or multiplying by 12? Is total units/ units removed giving us per month, so we multiply by 12 to get it for a year?
For instance if you have $\displaystyle \frac{2000 year}{500 year}$ the years unit cancels out from the numerator and denominator giving us an answer with no units??? If thats the case how are we able to multiply by 12?

Would some one please clarify, many thanks

2. Originally Posted by allyourbass2212
A book I am reading through lists the formula for months of supply in a word problem as

(total units)/(units removed)*12

For instance you have a stock of 2,000 PS3s and you removed 500 from your inventory for the year. What is your month of supply for PS3s? 2,000/500*12=48 months of supply. In other words Month of supply is the rate rate at which which you are selling PS3s, if you were to purchase no more to add to your stock, it would take 48 months to sell what you currently have at this current rate.

Problem: I dont understand why we are using division or multiplying by 12? Is total units/ units removed giving us per month, so we multiply by 12 to get it for a year?
For instance if you have $\displaystyle \frac{2000 year}{500 year}$ the years unit cancels out from the numerator and denominator giving us an answer with no units??? If thats the case how are we able to multiply by 12?

Would some one please clarify, many thanks
You are thinking about this problem in a great, analytical way but are just missing a tiny concept.

The amount of PS3's don't have units of "year". The conversion looks more like this:

$\displaystyle \frac{x \text{ units of whatever product}}{\text{y number of units sold per year}} \times \frac{\text{1 year}}{\text{12 months}} = \frac{x}{12y} \text{ units sold per month}$

The above is more of an explanation than the standard method of cancelling units, but I hope it's clear now. The number of units you begin with doesn't have the qualifying unit of years, it is just a number or a number of something like PS3's, etc. The denominator does have a unit of years, thus dividing by 12 or multiplying by 1/12 converts this to months.

3. Many thanks Jameson, that makes much more sense to me. I will take some time to make sure I understand it thoroughly and if I have any additional questions ill post here or perhaps PM you.

Thank again.

4. Originally Posted by allyourbass2212
Many thanks Jameson, that makes much more sense to me. I will take some time to make sure I understand it thoroughly and if I have any additional questions ill post here or perhaps PM you.

Thank again.
No, no no do not PM me or other members for help on problems. That's what the forums are for.

If you don't understand my explanation in my previous post, just ask and I'll clarify.