Q5: B as if y is positive we can use mod y in place of y

BTW, I am confused with your Q7? WHy not B an option? Why only A?

Hello,

Can you please post each question in a different thread, it will be easier for us to discuss and understand.
Moreover please write the complete question.

Thanks

Karan

Q1a
Is x^y>1?
1) x>1 - Insuff
2) Y<1 - Insuff
2^0.1 > 1
2^-2 < 1
IMO E

Q1b
Is x^y>1?
1) x>1 - Insuff
2) y>1 - Insuff
2^2 = 4
IMO C

Q2
Is x>0?
1) xy=0 ==> x and y are of different signs; Insuff
2) x+y= 0 ==> x and y are of different signs; Insuff
IMO E


Q3
Is x<0?
1) x^2<x^3 ==> x>0. If x<0 this cannot be possible
2) x^3<x^4 --- Possible when x>0 or x<0
IMO A



Q4a
Is lx+yl<lxl+lyl ? ==> Do x and y have different signs?
1)x-y>0 ==> x>y; Insuff
2) x+y>0 ==> x>-y; Insuff
IMO E

Q4b
Is lx+yl<lxl+lyl ? ==> Do x and y have different signs?
1)xy<0 ==> x and y have different signs.
2)x+y<0 ==> x and y need not have have different signs.
IMO A


Q5
Is lxl/y= lxl/lyl?
1)x<0 ==> Insuff
2) y>0 ==> Required to cancel y on both sides.
IMO B



Q6
st cannot be 0, If s-1/s<1/t-t, then s>t?
==> If t*s*s - t < s - s*t*t
<=> s*t*(s+t)<(s+t)
<=> If s*t < 1, then s>t?
1) s>2 --- Insuff
2) t<2 --- Insuff
s*t<1 iff either "s and t are fractions " or " s and t have different signs"
(1) removes the possibilithy that "s and t are fractions"
(1) and (2) and the given condition s*t < 1 says s>2 and t<0.5
So s>t
IMO C

Q7
xy+z=z, lx-yl>0??
==> If xy = 0 then |x-y|>0?
1) x cannot be 0 ---- Insuff
2) y cannot be 0 ---- Insuff
If x !=0 ;y!=0; xy=0; there is no x,y that can satisfy this. So cannot be determined. IMO E