breakkgmat wrote:I think its E as well.As it said Cost >=7.30..it could be any value on which the quantity of X & Y differ..But we would have got the answer if it had mentioned the exact Cost of it..
I edited my previous post for I noticed a mistake while specifying the answer.
While the answer for the original question has to be
B, the answer for the modified question is
E.
One efficient way of addressing questions involving inequalities is by using the graphical method.
Let's work on the original problem:
Given: X + Y = 1
6.5X + 8.5Y = C
Required:
Is X < 0.8
Statement 1:
Y> 0.15
This tells us that
X< 0.85[ Because of the first given]
Therefore, insufficient as
X can be 0.81, which is greater than 0.8, or
X can be 0.4, which is less than 0.8.[ Here I took 'X' values arbitrarily]
Statement 2:
C>= 7.3
Combining it with the second given,
6.5X + 8.5Y >=7.3
Now draw the graphs of
X + Y = 1 and
6.5X + 8.5Y >=7.3 [ Multiply both sides by 10 to simplify the process]
Find the common region, and you shall see that the portion from line X + Y =1 that is included in the
common region is that where
X<=0.6.[0.6 is a value of X at the intersection of the two lines drawn.]
Therefore, we know that the maximum
X can be is 6, which is
definitely less than 8. So, Sufficient!
Therefore,the answer is
B.
Now let's see the modified version of the problem:
The question was modified as follows:
Is X < O.6?
See that? We early on found that X
<=0.6. So, what shall we conclude?
X can be 0.6, in which case our answer is 'No!', but
X can also be 0.5, in which case our answer is 'Yes!'. Therefore, insufficient.
Both: Since statement 1 adds no unique information, Insufficient.
So, the answer is
E.
