Data Sufficiency

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Data Sufficiency

by ela07mjt » Tue Apr 16, 2013 11:54 pm
If b is positive, is ab positive?
(1) a^2*b > 0
(2) a^2 + b = 13

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by Anju@Gurome » Wed Apr 17, 2013 12:16 am
ela07mjt wrote:If b is positive, is ab positive?

(1) a²b > 0
(2) a² + b = 13
Note that both statements deals a² which is always positive but a can be either negative or positive. So, there is a pretty good chance that both statements together will not be sufficient.
Consider the following two examples,
  • a = 1 and b = 12 ---> ab positive
    a = -1 and b = 12 ---> ab negative
Both of the above examples satisfy both the statements but the answers are different in each case.

The correct answer is E.
Anju Agarwal
Quant Expert, Gurome

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