More Proportions Help

[Fragile Dreams]

Here's another one I don't completely understand:

<< A 3 lb bag of lawn seed covers 5000 sq ft. Lawn seed comes in 6 lb bags costing $7.50 and 3 lb bags costing $4.50. What is the smallest amount it would cost to cover a 24,000 sq ft area with lawn seed? >>

So far, I have:

    3lb
________

5000 sq ft

But I'm not quite sure what to do next...?

 

[Gene]

You also have = x/24000

 

[stapel]

Since "5000" doesn't fit neatly into "24,000", you're going to have to find some combination of bags which will work best. You will have some left over.

But different combinations will run to different amounts. Since the six-pound bag works out to be $1.25/lb and the three-pound bag works out to be $1.50/lb, it would probably be better to use one six-pound bag instead of two three-pound bags, where such a substitution will work.

See what you can do with this.

Eliz.

 

[Fragile Dreams]

Yes, I've done that and I end up with

    3 lb              14.4 lb
 _______   ·   ________

5000 sq ft     24,000 sq ft



How would I proceed to solve it?

 

[Gene]

You want as many 6# bags as possible and 1 3# bag to make the total area greater than 24000

 

[Fragile Dreams]

So would the answer be $180?

 

[stapel]

So would the answer be $180?

:shock:

Um... no; there is no reason to spend anywhere near that much.

I explained the basic reasoning and Gene provided specifics. Please reply showing the steps you took in following these instructions.

Thank you.

Eliz.