Is a

Question

Is a < b ?

(1) a^2 < ab 
(2) b < 0

Kinshook · Answer

Asked: Is ab But if a>0; ab; a<0; 0>a>b If a0; b>a>0; Not possible since b<0 0>a>b SUFFICIENT IMO C

Archit3110 · Answer

target is a<b
#1
a^2<ab
a(a-b)<0
a<0 or a<b
possible cases
when both a , b are -ve
-2(-2-(-4)) ; -8 ; no to target
2(2-4) ; -4 ; yes to target
insufficient
#2
b<0
insufficient
from 1 &2
yes as both a , b are -ve but a>b
option C

RenB · Answer

1. a^2<ab
ab is +ve since a^2 cant be -ve
a and b are both +ve or both -ve
a^2<ab means a*a<ab
a is common on both. Its the value of b that will impact the expression
If both +ve:
b>a
If both -ve:
b<a
No definite Y/N
Thus insufficient

2. No info about a

1+2:
b<0 thus both a and b are -ve
As discussed above for st.1, b<a
Thus definite answer
Hence sufficient

IMO C

Is a < b ? (1) a^2 < ab (2) b < 0

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