Gmatprep1 question, easy one

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Gmatprep1 question, easy one

by bkobilov » Thu Sep 23, 2010 11:45 am
Three boxes have an average (aithmetic) weight of 7 kilograms and a median weight of 9 kilograms. What is the maximum possible weight, in kilograms, of the lightest box?

A. 1
B. 2
C. 3
D. 4
E. 5

OA: C

Seems simple,
x+y+z=21 and lightest, 9, heaviest --> if heavy one is 10, then lightest is 2. But why it is incorrect?
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by diebeatsthegmat » Thu Sep 23, 2010 11:52 am
bkobilov wrote:Three boxes have an average (aithmetic) weight of 7 kilograms and a median weight of 9 kilograms. What is the maximum possible weight, in kilograms, of the lightest box?

A. 1
B. 2
C. 3
D. 4
E. 5

OA: C

Seems simple,
x+y+z=21 and lightest, 9, heaviest --> if heavy one is 10, then lightest is 2. But why it is incorrect?
ehhh i think you are wrong when consider the heaviest box is 10
to find the maximum number of the lightest box, we must minimum the other number
a+9+c=21 and c must be minimum thus it just can be 9, not 10

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by bkobilov » Thu Sep 23, 2010 11:57 am
oops, i though heaviest box can't 9 kgs, same as median. Thats why i took next integer-10.