一道没怎么读懂的DS题，求翻译&解答

wenyiwendy · 发表于 2011-6-30 00:05:08

Susan has selected exactly three crayons, each a different color, from a crayon box. How many crayon colors were represented in the box before her selection?(1) Exactly four distinct three-crayon color combinations were represented in the box before Susan selected three crayons.
(2) Just before Susan's selections, the box contained exactly five crayons.

wenyiwendy · 发表于 2011-6-30 00:06:21

我还没有检查完拼写怎么就发出去了呢？算了，答案是C。THX

sdcar2010 · 发表于 2011-6-30 01:47:46

(1) Exactly four distinct three-crayon color combinations were represented in the box before Susan selected three crayons.
From this, we know there are 4 possible combination of the selection, but we do not know how many crayons are in the box or how many different colors for these crayons.

(2) Just before Susan's selections, the box contained exactly five crayons.
From this, we know there are 5 crayons, but we do not know their respective colors.

(1) +(2), from this combination, we know there are 4 possible combination of colors for the selection and we know there are 5 crayons. If this is the case, then there are 3 colors and one of the color has 3 crayons while the other two has only one crayon.

A A A B C
ABC, AAB, AAC, AAA

一道没怎么读懂的DS题，求翻译&解答

所属分类: GMAT考试

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