Bunuel wrote:
Is \(ab < 0\)?
(1) \(ab^2 < b^2\)
(2) \(b^2 < b\)
Statement 1: \(ab^2-b^2<0\) or \(b^2(a-1)<0\). as \(b^2\) is always positive, this implies that \(a-1<0\)
or \(a<1\)--------------(1). but we don't know whether \(a\) is positive or negative and we don't have any information about \(b\). Hence
InsufficientStatement 2: \(b^2<b\). this implies that \(b\) is
positive and it is less than \(1\). so \(0<b<1\)
But we have no information about \(a\). Hence
InsufficientCombining 1 & 2 we don't know the sign of \(a\). if \(0<a<1\), then \(ab>0\) and if \(a<0\), then \(ab<0\). Hence
insufficientOption
E