If 5-lb bag of flour costs $3.99, find cost of 4 cups.

[mammarosales]

Question If a 5 pound bag of flour cost 3.99 how much would 4 cups of flour cost?

 

[sgtpepper]

Re: word problem

Okay, so you're trying to find 4 * (dollar/cup of flour)
So first you need to find how many dollars a pound of flour is. To do so, you divide the cost (3.99) of a 5 pound bag of flour by 5 (pounds):

3.99 / 5 = 0.80

so it's 80 cents for a pound of flour, then you need to convert pounds into cups:

1 pound is 16 ounces
8 ounces is 1 cup
so therefore, 1 pound is 2 cups.

This gives us 80 cents for 2 cups of flour. What you're looking for is the cost of 4 cups of flour. Multiply the cost of 2 cups for flour by 2 and you'll get the cost of 4 cups of flour!

http://tinyurl.com/yp4nu8

Hope this helps and that I didn't make any mistakes.

 

[stapel]

1 pound is 16 ounces
8 ounces is 1 cup

Not quite. While one pound of weight is sixteen ounces of weight, one cup of volume is eight fluid ounces. :shock:

Until we have some conversion factor between the weight of the flour and some measure of volume, we cannot proceed.

Sorry!

Eliz.

 

[sgtpepper]

I stand corrected:

1 pound of flour is equal to 4 cups of flour:
http://www.cdkitchen.com/features/data/ ... 5053.shtml

So working through that again with our new conversion factor, we have that a pound of flour is 80 cents. Then converting that to cups, we get that four cups of flour would cost one 80 cents... unless I made another error or erroneous assumption.

 

[stapel]

1 pound of flour is equal to 4 cups of flour

It depends on the flour. Even assuming we are speaking of modern bleached wheat general-purpose flour, one can find equivalences online ranging from 4.5 cups per pound all the way down to 2 [sup:15355ipj]2[/sup:15355ipj]/[sub:15355ipj]3[/sub:15355ipj] cups per pound. (A certain amount of this variation comes from whether or not the flour has been sifted.)

So we still need the conversion factor that was provided to the student in class and/or in the textbook. Until we know what conversion factor the poster is expected to use, there remains no way to be sure of the expected solution.

Eliz.