Ques 1

I think answer is B

x+y is integer is y an integer

Statement I

x-y is integer, this same as saying x+y is integer.

Insufficient.

Statement II

x+2y is integer, if x+y is integer & x+2y is integer, y and x both have to be integers.


Ques 2

I think the answer is E

Statement I

x and y are in ratio 7:9

for 63 x<y

for -63 x>y

Therefore insufficient.

Statement II

xy>0

x and y both are positive
or
x and y both are negative

Therefore, insufficient.

Combining I & II

xy>0
x/y=7/9

still have both the cases positive or negative.

Hence insufficient.

Whats are the OAs?

Q 1

WHAT IF X=1 AND Y=0.5
THEN X+ 2Y= 1 +2*.5=2 AND INTEGER
Also X= 0.8 and Y=0.1

So B is also InSuff...

Opt 1.
X-Y will only be integer when x=y ( incase anyone or both x or y is non integer)

Wld go for C ( Both options are reqd.. to solve this problem)

classic wrote:Q 1

WHAT IF X=1 AND Y=0.5
THEN X+ 2Y= 1 +2*.5=2 AND INTEGER
Also X= 0.8 and Y=0.1

So B is also InSuff...

Opt 1.
X-Y will only be integer when x=y ( incase anyone or both x or y is non integer)

Wld go for C ( Both options are reqd.. to solve this problem)

"WHAT IF X=1 AND Y=0.5" this cannot happen because the question says X+Y is an integer and 1+0.5 is not an integer... so u cant that assumption..

hope its clear..

1. B

2. E

-----------------------------
Thx for answer, from them, I understand Q1,
but Q2's condition 1).. I can't still get it.
Because
x : y = 7 : 9 <-- This mean that y is bigger than x, right?
so, I think the answer is A, not E.
But officially the answer is E.
This is my problem.

Goodlife wrote:1. B

2. E

-----------------------------
Thx for answer, from them, I understand Q1,
but Q2's condition 1).. I can't still get it.
Because
x : y = 7 : 9 <-- This mean that y is bigger than x, right?
so, I think the answer is A, not E.
But officially the answer is E.
This is my problem.

I will try to explain u the 2nd question.
Is x < y ?
(1) The ratio of x to y is 7/9.
(2) xy > 0

if u take the first case... asssume that X is 49 and Y is 63
then the ratio is 7:9 and X<Y but what if X is -49 and Y is -63 .. even in that case the ratio is 7:9 but here X>Y.

so statement 1 is insufficient..

Statement 2 .. use the same number..
X=49, Y=63 XY>0 and X>Y

but if X=-49 and Y =-63 still XY>0 but X<Y

hence in sufficient .. Even with both ur not sure abt the signs of the numbers

Therefore the answer is E.

hope it helps.. do let me know if u have any doubts..