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Finding the Amount of Cement Needed to Fill an Area


Date: 11/1/95 at 19:12:42
From: Anonymous
Subject: Math problem

I have an area 16 feet by 16 feet and two inches deep.  If I fill 
it with cement, how many bags of cement do I need?  1 80 lb bag 
make 2/3 cubic feet...


Date: 11/6/95 at 1:32:36
From: Doctor Jonathan
Subject: Re: Math problem

Tony:

Well, you first need to know the volume that you need to fill.  
This would be 16*16*(1/6) cubic ft. (1/6 feet is two inches.) 
Now you know the volume of cement produced by each bag, right? 
(The fact that each bag is 80 lb doesn't matter.) So you want to 
know how many times 2/3 goes into 16*16/6.

If you still need more help, feel free to write back.

-Doctor Jonathan,  The Geometry Forum


Date: 11/9/95 at 11:38:14
From: Anonymous
Subject: Math problem

So the answer would be 128 bags...


Date: 11/12/95 at 23:40:44
From: Doctor Jonathan
Subject: Re: Math problem

Well, I actually got 64. It looks like in the final division you 
forgot to divide by two at the end.  (To divide any number by 2/3, 
you can multiply it by three and divide by two.)

-Doctor Jonathan,  The Geometry Forum

    
Associated Topics:
Middle School Higher-Dimensional Geometry

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