DS1

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Source: — Data Sufficiency |

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by clock60 » Tue Jul 19, 2011 10:03 am
we need to estimate whether:r/(r+b+w)>w/(r+b+w), or simply does R>W?
(1) given that r/(b+w)>w/(b+r)
one important note here
total=t=r+b+w
b+w=t-r-for left part of the inequality
b+r=t-w for the right part of the inequality
r/(t-r)>w/(t-w) now cross-multiply
rt-wr>wt-wr. cancel wr and left with rt>wt, cancel t and left with r>w
so suff.
(2) second st has plenty of options so insuff

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by ruplun » Wed Jul 20, 2011 6:47 am
thanks