Algebra Question

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Algebra Question

by smishrajec » Mon Apr 09, 2012 6:29 am
One question from GMAT prep is haunting me? I could not simplify the way to reach the answer. Please suggest some simple way to answer following types of question.

a^4+b^4=100. What can be the maximum value of "a" in the following range?
1. (1,2)
2. (2,3)
3. (3,4)
4. (4,5)

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by GMATGuruNY » Mon Apr 09, 2012 6:41 am
smishrajec wrote:One question from GMAT prep is haunting me? I could not simplify the way to reach the answer. Please suggest some simple way to answer following types of question.

a^4+b^4=100. What can be the maximum value of "a" in the following range?
1. (1,2)
2. (2,3)
3. (3,4)
4. (4,5)
To MAXIMIZE one value, try to MINIMIZE the other values.
The smallest possible value of b� is 0.
Thus, the MAXIMUM possible value of a� is 100.
Since 3�=81 and 4�=256, the maximum possible value of a is between 3 and 4.
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by smishrajec » Mon Apr 09, 2012 6:58 am
Thanks Mitch!!!!!!
It works with other questions of same types too...