Please help me with this question. I totally have no idea why the options have decimals(Worried) Thank you (Hi)

http://i.imgur.com/riiYT.png

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- May 7th 2011, 10:44 AMmathbuoyRings Question
Please help me with this question. I totally have no idea why the options have decimals(Worried) Thank you (Hi)

http://i.imgur.com/riiYT.png - May 7th 2011, 12:41 PMOpalg
Notice that when the chain hangs vertically, the rings are alternately in one of two planes,

*either*in the same plane as the top ring*or*in a perpendicular plane. If the chain has an odd number of rings in it, then the bottom ring will have a whole number of 180º twists. But if the chain has an even number of rings then the bottom ring must have an additional half-twist. - May 7th 2011, 07:24 PMmathbuoy
Thank you explaining!!

Is my reasoning below right?

if it's two rings, the bottom ring makes .5 twist.

if there're 3 rings, the bottom ring makes .5 + .5 twist.

if there're 6 rings, it should be 2.5 twist.

The answer is B(.5, 1.5, 2.5) but i don't understand why it's given as .5, 1.5 and 2.5 and not just 2.5 twist. - May 8th 2011, 01:27 AMOpalg
- May 9th 2011, 06:22 AMmathbuoy
But why can't the other answers apply?

- May 9th 2011, 06:31 AMOpalg