Data Sufficiency (DS) | Re: Is zw positive?

Que, zw = + ve ?

1. z + w ^3 = 20
w = 1,2,3 ........ if w = 1 ^3 = 1 , 2^3 =8 , 3^3 = 27
if w = (-1)^3 = -1 , (-2) ^3 = -8
s0, zw can be +ve or -ve
not sufficient
2. z = +ve
w = 1,2,3 ........ if w = 1 ^3 = 1 , 2^3 =8 , 3^3 = 27
if w = (-1)^3 = -1 , (-2) ^3 = -8
zw can be +ve or -ve
not sufficient

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