How to resolve a set?

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How to resolve a set?

by Fokin » Tue Apr 27, 2010 6:15 pm
If each of the 20 bolts of fabric on a shelf is either 100 percent cotton, 100 percent wool, or a mixture of cotton and wool, how many bolts are cotton and wool mixtures?

1. Of the 20 bolts, 18 contain some wool and 14 contain some cotton.

2. Of the 20 bolts, 6 are 100 percent wool.
Source: — Data Sufficiency |

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by liferocks » Tue Apr 27, 2010 6:24 pm
From 1
18 have some wool..hence 20-18=2 are 100% cotton
now 14 have some cotton
hence 14-2=12 are mix of cotton and wool
--Sufficient

From 2 we cannot conclude the number of mix bolt
Ans A

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by GMATinsight » Thu Oct 08, 2015 1:06 am
Fokin wrote:If each of the 20 bolts of fabric on a shelf is either 100 percent cotton, 100 percent wool, or a mixture of cotton and wool, how many bolts are cotton and wool mixtures?

1. Of the 20 bolts, 18 contain some wool and 14 contain some cotton.

2. Of the 20 bolts, 6 are 100 percent wool.

Let, 100 Cotton = C
100 Wool = W
Mixture of cotton and wool = M

Given, C+W+M = 20

Question : M=?

Statement 1: Of the 20 bolts, 18 contain some wool and 14 contain some cotton.
i.e. W+M = 18 and C+M = 14
we know, C+W+M = 20
i.e. C = 2, W=6 and M= 12
SUFFICIENT

Statement 2:Of the 20 bolts, 6 are 100 percent wool.
W=6
i.e. C+M=14
NOT SUFFICIENT

Answer: option A
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