Since y > 0 we can first rephrase the question stem:
Is X < 3Y?
(1) factoring the (x + y) common factor:
(X + Y) (X - 4Y) < 0
Since the product is less than 0, the factors must have opposite signs. So we have two possible cases:
Case 1:
(X + Y) < 0
And
(X - 4Y) > 0
Which means:
X < -Y
And
X > 4Y
Since Y is a positive value, it means that if Y were +1, for instance, these inequalities would be impossible to coexist
X <-1 ——-and——— X > 4
X can not simultaneously be less than a (-)negative number and greater than a (+)positive number. So it must be the other case
Case 2:
(X + Y) > 0
and
(X - 4Y) < 0
X > -Y —- and —— X < 4Y
Combining the inequalities:
-Y < X < 4Y
*Q* is: X < 3Y?
Not sure:
Can have
-Y < 3Y < X < 4Y ——> NO
OR
-Y < X < 3Y < 4Y ——> YES
S1 not sufficient
(2)
5Y + 40 < 20Y - 3X + 40
3X < 15Y
X < 5Y
*Q* is X < 3Y?
Not sure —- S2 is not sufficient alone
Together: statement 2 does not add any more of a restrictive condition on X
All we know for sure is that: X < 4Y
We do not know whether: X < 3Y
Answer
E
Posted from my mobile device