nidhis.1408 wrote:Is bd <0
(1) bc < 0
(2) cd >0
Can somebody please give me the answer with explanation. I am a little confused!
Hi nidhis.1408:
The easiest way to do this one is to understand what the question is asking and rephrase it.
Is bd<0 translates to: do b and d have opposite signs?
With that in mind let's look at the statements.
(1) bc < 0
Here bc<0 tells us that b and c have opposite signs. It doesn't tell us anything about d. Insufficient.
(2) cd >0
Here cd>0 tells us that c and have the same sign. It doesn't talk about b. Insufficient.
Together,
b and c have opposite signs and c and d have the same sign. Hence, b and d have opposite signs. So bd<0. Sufficient.
Let me know if this helps
