Data Sufficiency #115

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Data Sufficiency #115

by Chick » Mon Nov 16, 2009 1:58 pm
For any integers x and y, min(x, y) and max(x, y) denote the minimum and the maximum of x and y, respectively. For example, min(5, 2) = 2 and max(5, 2) = 5. For the integer w, what is the value of min(10, w) ?

(1) w = max(20, z) for some integer z.
(2) w = max(10, w)

Ans: D

Based on the GMAT answer explanation, statement (1) is sufficient because "w = max(20, z) for some integer z" implies that w is > or = 20, indicating that min(10, w) = 10...

and statement (1) is sufficient because "w = max(10, w)" implies that w is > or = 10.

Although I do understand this answer, it took me way too long to answer. Can anyone explain another (perhaps algebraic approach) to solve this problem?

Thanks.
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by palvarez » Mon Nov 16, 2009 2:22 pm
1. w = max(20, z) = 20 or 20+k--the latter because z > 20
min (10, 20) or min (10, 20+k) = 10

2. w = max(10, w), w has to be 10+m, m>=0

min(10, 10+m) = 10