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Re: Real life story problem help
Posted:
Jun 6, 2005 6:12 PM


jackjohansson@gmail.com writes: >Now balloons are listed as "12 inches". I am guessing that an >inflated balloon, and empty space around it when it is put in a large >room with other balloons would equal maybe 1.25 cubic feet.
If the balloon has a onefoot diameter, that doesn't mean it occupies one cubic foot when inflated! That would be true if the balloon were cubical in shape, rather than spherical.
The volume of a cube is 4/3 pi r^3. Your radius is 1/2 foot, so your volume is pi/6 which is about 0.524 cubic feet.
You're right that there will be some empty air space (depending on how tightly you cram the balloons in  you could *force* them to be more or less cubical (and smaller than advertised) if you really try hard  but still, you'll need more balloons, not fewer, than you would if each balloon occupied exactly one cubic foot.
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